Page 1
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD)
sensor, ignitor assemblies (in air bag modules), clockspring and associated wiring harnesses. See
Fig. 1
.
1997 Ford Pickup F150
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Bag Restraint System
1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air Bag Restraint System
IDENTIFICATION
WARNING: To avoid injury from accidental air bag deployment, read and carefully
follow all WARNINGS and SERVICE PRECAUTIONS .
Vehicle is equipped with driver-side air bag which is identified by a letter "L" in fourth position of Vehicle
Identification Number (VIN). VIN is located on top of instrument panel, near lower left corner of windshield.
VIN is also stamped on Vehicle Certification (VC) label, mounted on left front door pillar.
The words Supplemental Restraint System (SRS) are embossed on steering wheel center hub. A label denoting
that vehicle is equipped with air bag is affixed to driver-side sun visor.
DESCRIPTION & OPERATION
The Supplemental Restraint System (SRS) is designed to provide increased accident protection for driver and
passenger by deploying air bags in a front-end collision. The air bags, stored in center of steering wheel and in
instrument panel above glove box, deploy in about 40 milliseconds after impact sensors close. SRS is designed
to be used with 3-point safety belts.
During a front-end collision of sufficient force, both a front impact sensor and a safing sensor will activate
simultaneously to inflate air bag. When a front impact sensor and safing sensor are closed at same time,
electrical current will flow, igniting the driver-side and passenger-side air bag module.
SRS includes following components: diagnostic monitor, driver-side air bag module, passenger-side air bag
module and deactivation switch, SRS readiness light (AIR BAG warning light), front impact sensor and safing
Page 2
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 1: Locating SRS Components
Courtesy of FORD MOTOR CO.
Page 3
BACK
-
UP POWER SUPPLY
up power supply will deploy air
check and whenever
PASSENGER
-
SIDE AIR BAG DEACTIVATION SWITCH
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
A back-up power supply is used on all models and is located inside diagnostic monitor. If battery or battery
cables are damaged in a collision before front impact sensors close circuit, backbag. Back-up power supply will hold a deployment charge for approximately one minute after positive battery
cable is disconnected.
CLOCKSPRING
The steering column contains a clockspring to transfer electrical signals from steering column wiring harness to
driver-side air bag module. Clockspring is mounted to steering column behind steering wheel.
DIAGNOSTIC MONITOR
The diagnostic monitor (located on left side of steering column underneath instrument panel) contains a
microcomputer, which monitors electrical system components and connections. Diagnostic monitor performs a
system self-check of SRS internal circuits every time ignition switch is turned to RUN position. Monitor also
energizes SRS readiness indicator light (AIR BAG warning light) during initial system selfa fault is detected. Faults are translated into flash codes and are displayed through AIR BAG warning light.
If a system fault exists and/or AIR BAG warning light is malfunctioning, an audible tone will sound, indicating
need for service. See TONE GENERATOR . Diagnostic monitor can also disarm SRS if certain faults occur.
The air bag diagnostic monitor does not deploy air bags in the event of a collision. The right or left front impact
sensors and safing sensor determine air bag deployment. The safing sensor is internal to air bag diagnostic
monitor and is not replaced separately.
DRIVER-SIDE AIR BAG MODULE
The driver-side air bag module is mounted on center of steering wheel, covered by steering wheel trim cover.
When a front impact sensor and safing sensor close, signaling an impact, ignitor triggers inflator. During
ignition, sodium azide reacts with copper oxide, producing nitrogen gas, which inflates air bag.
When air bag deploys, tear-seams molded into steering wheel trim cover separate, allowing inflation of air bag
assembly. Driver-side air bag module is not serviceable and must be replaced as a complete assembly.
PASSENGER-SIDE AIR BAG MODULE
The passenger-side air bag module is mounted in right side of instrument panel, above glove box. When a front
impact sensor and safing sensor close, signaling an impact, air bag igniters trigger inflator.
Since passenger-side air bag is larger than driver-side air bag, inflator contains more gas generant in a different
configuration to produce more gas. When air bag is activated, instrument panel trim cover tears at seams and
hinges, allowing inflation. Passenger-side air bag module is only serviced as a complete assembly.
Page 4
The Passenger
-
side Air bag Deactivation (PAD) switch is located on center instrument panel, below climate
light, stay on continuously, or flash a code sequence. If AIR BAG warning light flashes, indicating a fault
If a system fault exists and AIR BAG warning light fails to light, an audible tone will be heard, indicating
under DESCRIPTION
These precautions should be observed when working with SRS:
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
control vent, and contains a light diode (LED) that indicates when PAD switch is activated. This switch allows
the passenger-side air bag deployment circuit to be disabled by inserting ignition key into PAD switch lock
cylinder and turning key. It should be used whenever child safety seat is being used in front passenger-side
seating position.
ELECTRICAL SYSTEM
SRS is powered directly from battery and can function with ignition switch in any position, including OFF and
LOCK. System can also function when driver-side seat is unoccupied. The 3 main functions performed by
electrical subsystem are: detecting an impact, switching electric power to igniters for air bag, and monitoring
readiness of SRS.
FRONT IMPACT SENSORS
Front impact sensors are located at right and left sides of radiator support. Each impact sensor reacts to impacts
according to direction and force. It discriminates between impacts that require air bag inflation and impacts that
do not.
When an impact occurs requiring air bag inflation, impact sensor contacts close, completing electrical circuit
necessary for system operation. At least 2 sensors, safing sensor and one front impact sensor, must be activated
simultaneously to inflate air bag.
TONE GENERATOR
AIR BAG warning light is prime means of determining SRS condition; however, a series of 5 audible tones,
indicating that system requires servicing, will sound if AIR BAG warning light is out, and a fault occurs in
system. Unless serviced, SRS may not function properly in an accident. Tone generator is located within
diagnostic monitor.
SYSTEM OPERATION CHECK
1. When checking SRS operation, and upon completion of each diagnostic test, check for faults in SRS. To
check system, turn ignition switch to RUN position. If AIR BAG warning light illuminates for 4-8
seconds and then goes out, SRS is functioning properly and no fault codes exist.
2. If a fault code is detected in SRS during initial system check, AIR BAG warning light will either fail to
in system, count number of flashes after fault code has cycled twice. Number of flashes represents a code
number used to diagnose SRS. See DIAGNOSIS & TESTING .
3.
AIR BAG warning light is out and service is required. See TONE GENERATOR
& OPERATION.
SERVICE PRECAUTIONS
Page 5
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Disable SRS before servicing any SRS or steering column components. Failure to do so may result in
accidental air bag deployment and personal injury. See procedures under DISABLING &
ACTIVATING AIR BAG SYSTEM .
Wait one minute after disabling SRS before working on vehicle. Back-up power supply holds a
deployment charge for approximately one minute after positive battery cable is disconnected. Servicing
SRS before one minute may cause accidental air bag deployment and possible personal injury.
Because of critical system operating requirements, DO NOT service impact sensors, clockspring,
diagnostic monitor or air bag module. Repairs are made by replacement only.
Always wear safety glasses whenever servicing an air bag equipped vehicle or handling an air bag.
When carrying a live air bag module, ensure air bag module and trim cover are pointed away from your
body. This minimizes chance of injury in event of an accidental deployment.
When placing a live air bag module on a bench or other surface, always face air bag module and trim
cover facing up and away from surface. This will reduce motion of module if it is accidentally deployed.
After deployment, air bag surface may contain deposits of sodium hydroxide, which may irritate skin.
Sodium hydroxide is a product of gas generant combustion. Always wear gloves and safety glasses when
handling a deployed air bag. Wash your hands using mild soap and water. Follow correct disposal
procedures. See DISPOSAL PROCEDURES .
If scrapping a vehicle with an undeployed air bag module, air bag must be deployed. See DISPOSAL
PROCEDURES .
If a part is replaced and new part does not correct condition, reinstall original part and perform diagnostic
procedure again.
Never probe connectors on air bag module. Doing so may cause air bag deployment and/or personal
injury.
Instruction to disconnect always refers to connector. DO NOT remove component from vehicle if
instructed to disconnect.
After any servicing, ensure AIR BAG warning light does not indicate any fault codes. See SYSTEM
OPERATION CHECK .
Replace air bag module if trim cover (deployment doors) is marred or damaged. DO NOT repaint trim
cover. Paint may degrade cover material. Replace air bag module as necessary. See PROCEDURE 1
under SCRAPPED VEHICLE under DISPOSAL PROCEDURES.
DISABLING & ACTIVATING AIR BAG SYSTEM
WARNING: Wait one minute after disabling SRS before working on vehicle. Back-up
power supply holds a deployment charge for approximately one minute
after positive battery cable is disconnected. Servicing SRS before one
minute may cause accidental air bag deployment and possible personal
injury.
CAUTION: When battery is disconnected, vehicle computer and memory systems
may lose memory data. Driveability problems may exist until computer
systems have completed a relearn cycle. See COMPUTER RELEARN
PROCEDURES in GENERAL INFORMATION before DISCONNECTING
Page 6
Wait at least one minute before servicing any air bag components. System is now disabled. To activate SRS, see
switch to RUN position. Check AIR BAG warning light for system fault codes. Perform system operation check
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
BATTERY.
DISABLING SYSTEM
NOTE: Following disabling procedure should be used for component replacement
purposes only. If vehicle was involved in a collision and air bag did not deploy
or if SRS is not functioning properly, and vehicle needs to be driven, complete
system deactivation is required. See COMPLETE SYSTEM DEACTIVATION .
Disconnect ground battery cable. SRS contains a back-up power supply built into air bag diagnostic monitor.
ACTIVATING SYSTEM .
ACTIVATING SYSTEM
Connect ground battery cable. System is now activated. From outside of vehicle (driver-side), turn ignition
to ensure SRS is functioning properly. See SYSTEM OPERATION CHECK .
COMPLETE SYSTEM DEACTIVATION
WARNING: Back-up power supply will hold a deployment charge for approximately
one minute after positive battery cable is disconnected. Servicing SRS
before one minute may cause accidental air bag deployment and possible
personal injury. Always deactivate driver-side module before attempting
any service procedures.
NOTE: Complete system deactivation sequence is required for following situations:
Vehicle was involved in a collision, air bag did not deploy, and vehicle needs to be driven.
SRS is not functioning properly, and vehicle needs to be driven.
Diagnosis and testing purposes.
1. Disconnect ground battery cable. Wait at least one minute to deplete charge in back-up power supply.
Remove driver-side air bag module. See DRIVER-SIDE AIR BAG MODULE under REMOVAL &
INSTALLATION. Connect Air Bag Simulator (105-00010) to harness at top of steering column.
2. Remove passenger-side air bag module. See PASSENGER-SIDE AIR BAG MODULE under
REMOVAL & INSTALLATION. Connect Air Bag Simulator (105-00010) to harness in place of air bag
module. Reconnect ground battery cable. To reactivate SRS, see COMPLETE SYSTEM
REACTIVATION
Page 7
side
INSTALLATION. Reconnect ground battery cable. System is now reactivated. Check AIR BAG warning
Scrapping vehicle with live air bag.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 2: Installing Air Bag Simulator
Courtesy of FORD MOTOR CO.
COMPLETE SYSTEM REACTIVATION
1. Disconnect ground battery cable. Wait at least one minute to deplete charge in back-up power supply.
Remove Air Bag Simulator (105-00010) from harness connector at steering wheel. Install driver-side air
bag module. See DRIVER-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION.
2. Remove Air Bag Simulator (105-00010) from harness connector on passenger-side. Install passengerair bag module. See PASSENGER-SIDE AIR BAG MODULE under REMOVAL &
light for proper system function. See SYSTEM OPERATION CHECK .
DISPOSAL PROCEDURES
WARNING: Refer to SERVICE PRECAUTIONS before proceeding.
Air bag disposal may be necessary in following situations:
Scrapping vehicle with deployed air bag.
Page 8
If vehicle is to be scrapped, undeployed air bag module must first be deployed. Use one of following procedures
side air bag is to be scrapped, but a problem in air
bag electrical system prevents deployment with air bag still installed in vehicle. This procedure can also be used
Dispose Of In Usual
Dispose Of In Usual
Deploy Air Bag Using
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Disposal of a live but electrically faulty air bag module.
Disposal of a deployed air bag module.
AIR BAG DISPOSAL PROCEDURES
Condition Instructions
Module Replacement
Deployed Air Bag
(1)
Manner
Faulty But Live Air Bag Module
(2)
Return For Disposal
Vehicle To Be Scrapped
Deployed Air Bag
(1)
Manner
Live Air Bag
(3)
PROCEDURE 1
(1)
See DEPLOYED AIR BAG .
(2)
See UNDEPLOYED AIR BAG .
(3)
See SCRAPPED VEHICLE .
DEPLOYED AIR BAG
Dispose of deployed air bag module as any other part. Air bag module components are not reusable.
UNDEPLOYED AIR BAG - FAULTY UNIT
If an undeployed air bag module is diagnosed as faulty, remove air bag module and return intact to Ford Motor
Company for proper disposal. Return carton for warranty claim credit. Air bag must be packaged and shipped
according to U.S. Department of Transportation. Retain replacement packaging including label. DO NOT
deploy air bag.
SCRAPPED VEHICLE
CAUTION: DO NOT dispose of undeployed air bag module without first deploying air
bag. If this is not possible through procedures outlined, contact vehicle
manufacturer for further instructions.
for deployment of air bag.
Procedure 1: Remote Deployment Of Air Bag
This procedure is to be used when a vehicle with a live driver-
Page 9
if PROCEDURE 1 was unsuccessful.
or field. Remain at least 20 feet away from air bag module. Deploy air bag by touching loose ends of both
All wire splice connections must be staggered at least 2" (50 mm) apart.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
WARNING: Perform remote deployment outdoors. Keep all personnel at least 20 feet
away to ensure physical and hearing safety from projected objects and
loud noise of air bag deployment.
1. Before proceeding, see SERVICE PRECAUTIONS . Deactivate SRS. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Remove driver-side and/or passenger-side air bag module. See
DRIVER-SIDE AIR BAG MODULE and PASSENGER-SIDE AIR BAG MODULE under REMOVAL
& INSTALLATION .
2. With air bag module removed, cut air bag connector from wiring harness near air bag module. Strip 1" of
insulation from wire ends. Obtain 2 wires at least 20 feet long. Connect one end of each 20-foot wire to
one end of each air bag module wire.
WARNING: When placing a live air bag on a bench or other surface, always face
air bag and trim cover up and away from surface. This will reduce
motion of air bag module if it is accidentally deployed.
3. Place air bag module with trim cover facing upward on a flat surface, in remote area such as parking lot
wires to 12-volt battery terminals.
4. If successful, a loud noise will be heard and bag material will be visible. Allow at least 10 minutes for
cooling and dissipation of air bag effluents before approaching air bag. Air bag is now inoperative. If air
bag does not deploy, air bag module is faulty. Contact vehicle manufacturer for further instructions on
disposal procedures.
POST-COLLISION INSPECTION
When a vehicle has been involved in a collision, certain components of the passive restraint system must be
inspected or replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the GENERAL
INFORMATION section for post-collision inspection information.
ADJUSTMENTS
CLOCKSPRING
Rotate clockspring rotor counterclockwise until it stops, then rotate clockwise two revolutions. Clockspring is
now aligned.
WIRE REPAIR
To repair damage to sensor wiring and wiring harnesses, note the following conditions and proceed to REPAIR
PROCEDURE.
Page 10
together. Solder connection using rosin core, mildly activated solder. Flatten connection against wires, and slide
gun, hair dryer, or match, heat tubing until it shrinks and adhesive oozes from each end of tubing. Connection is
now waterproofed.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Use appropriate solder (rosin core) and proper size heat shrink tubing for size of wire being spliced.
All repaired connections must be waterproofed using heat shrink tubing.
Repair Procedure
Bag Restraint System
Cut shrink tubing about 2" long. Slide shrink tubing onto one wire end first. Strip wire ends and twist firmly
heat shrink tubing over solder joint leaving 1/2" of tubing on each side of connection. See Fig. 3 . Using heat
Page 11
REMOVAL & INSTALLATION
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 3: Repairing & Waterproofing Wiring Connections
Courtesy of FORD MOTOR CO.
Page 12
holding wire to column. Remove clockspring, feeding wiring harness through instrument panel.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
WARNING: Failure to follow service precautions may result in air bag deployment
and personal injury. See SERVICE PRECAUTIONS . After component
replacement, ensure proper system operation. See SYSTEM OPERATION
CHECK .
CAUTION: When battery is disconnected, vehicle computer and memory systems
may lose memory data. Driveability problems may exist until computer
systems have completed a relearn cycle. See COMPUTER RELEARN
PROCEDURES in GENERAL INFORMATION before disconnecting battery.
CLOCKSPRING
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Ensure vehicle front wheels are in straight-ahead position and steering column shaft alignment mark is at
12 o'clock position.
2. Remove driver-side air bag module. See DRIVER-SIDE AIR BAG MODULE . Twist tilt wheel handle
and shank and remove, if equipped. Remove lower steering column shroud. Remove ignition switch lock
cylinder by inserting key into ignition and turn to RUN position, then push in release tab while pulling
out ignition switch.
3. Carefully pry to release clips and remove steering column opening cover. Remove upper steering column
shroud. Clockspring contains lock to prevent rotation during steering wheel removal. If lock is missing,
apply two tape strips across clockspring and housing to prevent rotation. See Fig. 4 .
4. Remove the key-in ignition warning light switch. Disconnect clockspring electrical connector and
separate connector from bracket. Pry retaining clips loose and separate wire from two retaining clips
Page 13
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 4: Preventing Clockspring Rotation
Courtesy of FORD MOTOR CO.
Page 14
clockspring. Rotate wiring and secure into two wire clips.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 5: Removing Clockspring From Steering Column
Courtesy of FORD MOTOR CO.
Installation
1. Ensure vehicle front wheels are in straight-ahead position and steering column shaft alignment mark is at
12 o'clock position. Clockspring contains lock to prevent rotation during steering wheel removal. If lock
is missing clockspring must be realigned. See CLOCKSPRING under ADJUSTMENTS .
2. Properly orientate clockspring: air bag electrical pigtail should point to three o'clock position, and dot on
steering shaft should be at nine o'clock position. Press at six, twelve, and three o'clock positions to install
Page 15
retaining diagnostic monitor to bracket. Remove diagnostic monitor. See
Fig. 6
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
3. Connect two clockspring electrical connectors and snap into bracket. Install key-in ignition warning light
switch. If installing new clockspring, remove Yellow anti-rotation tab. Install upper and lower steering
column shroud and opening cover. Install tilt wheel handle and shank, if equipped.
4. Install steering wheel. See STEERING WHEEL . Install driver-side air bag module. See DRIVER-
SIDE AIR BAG MODULE . Reactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Check AIR BAG warning light for proper system function. See SYSTEM OPERATION
CHECK .
DIAGNOSTIC MONITOR
CAUTION: When replacing air bag diagnostic monitor, with blown internal thermal
fuse all short circuits and damaged wiring has been repaired. Diagnostic
portion of diagnostic monitor is still intact, and must be used to diagnose
and verify repairs before diagnostic monitor replacement.
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2. Remove right cowl side trim panel. Disconnect diagnostic monitor electrical connectors. Remove screws
Page 16
. Disconnect horn and clockspring electrical connectors from air bag
module. Remove air bag module from steering wheel.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 6: Removing Air Bag Diagnostic Monitor
Courtesy of FORD MOTOR CO.
Installation
To install diagnostic monitor, reverse removal procedure. Activate air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning light for proper system function. See
SYSTEM OPERATION CHECK .
DRIVER-SIDE AIR BAG MODULE
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2. Remove cover plugs on back side of steering column to access and remove screws retaining air bag
module to steering wheel. See Fig. 7
Page 17
passenger
-
side air bag module electrical connector. Remove air bag module. See
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 7: Removing Driver-Side Air Bag Module
Courtesy of FORD MOTOR CO.
Installation
To install, reverse removal procedure. Tighten screws to specification. See TORQUE SPECIFICATIONS .
Activate SRS. See procedures under DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG
warning light for proper system function. See SYSTEM OPERATION CHECK .
PASSENGER-SIDE AIR BAG MODULE
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2. Remove instrument panel relay cover. Remove three air bag module retaining screws. Disconnect
Fig. 8
Page 18
To install, reverse removal procedure. Tighten screws to specification. See
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 8: Removing Passenger-Side Air Bag Module
Courtesy of FORD MOTOR CO.
Installation
To install, reverse removal procedure. Tighten air bag module retaining screws to specification. See TORQUE
SPECIFICATIONS . Activate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR
BAG warning light for proper system function. See SYSTEM OPERATION CHECK .
PAD SWITCH
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2. Remove center instrument panel finish and relay cover. Disconnect two passenger-side air bag
deactivation (PAD) switch electrical connectors. Remove three screws retaining PAD switch and PAD
switch.
Installation
TORQUE SPECIFICATIONS
Page 19
Activate SRS. See procedures under
DISABLING & ACTIVATING AIR BAG SYSTEM
. Check AIR BAG
Front impact sensors are located on right and left of radiator support. Remove eight push clips on radiator
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
warning light for proper system function. See SYSTEM OPERATION CHECK .
FRONT IMPACT SENSORS
Removal
1. Before proceeding, read and carefully follow all air bag service precautions. See SERVICE
PRECAUTIONS . Disable SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2.
shield and radiator air deflector. Disconnect right and/or left front impact sensor electrical connector(s).
Remove sensor retaining screws from bracket. Remove right and/or left front impact sensor. See Fig. 9 .
Fig. 9: Removing Front Impact Sensors
Courtesy of FORD MOTOR CO.
Installation
To install, reverse removal procedure. Tighten screws to specification. See TORQUE SPECIFICATIONS .
Activate SRS. See procedures under DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG
warning light for proper system function. See SYSTEM OPERATION CHECK .
STEERING WHEEL
Page 20
Removal
New Generation Star (NGS) tester with brief description of fault. Faults detected during self test are not stored
in memory, unless same fault was detected during normal vehicle operation. Self test should be run after service
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
1. Center front wheels to straight-ahead position. Before proceeding, read and carefully follow all air bag
service precautions. See SERVICE PRECAUTIONS . Disable air bag system. See procedures under
DISABLING & ACTIVATING AIR BAG SYSTEM . Remove air bag module from steering wheel.
See DRIVER-SIDE AIR BAG MODULE .
2. Disconnect horn and clockspring electrical connector from steering wheel. Remove steering wheel
retaining bolt. Mark steering wheel hub and steering shaft for installation reference. Remove steering
wheel using steering wheel puller. Route clockspring (contact assembly) wiring harness through steering
wheel as wheel is lifted from steering shaft.
Installation
1. Ensure front wheels are in straight-ahead position. Route clockspring wiring harness through steering
wheel opening at 3 o'clock position. Position steering wheel on steering shaft and align marks made
during removal procedure.
2. Ensure air bag clockspring wire is not pinched when positioning steering wheel. Install new steering
wheel retaining bolt, and tighten to specification. See TORQUE SPECIFICATIONS . Connect
horn/speed control wiring harness (if equipped) to steering wheel and snap connector assembly into
steering wheel clip.
3. Install air bag module. Reconnect positive, then negative battery cable. Activate SRS. See DISABLING
& ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning light for proper system function.
See SYSTEM OPERATION CHECK .
DIAGNOSIS & TESTING
WARNING: Failure to follow service precautions may result in air bag deployment
and personal injury. See SERVICE PRECAUTIONS . After component
replacement, ensure proper system operation. See SYSTEM OPERATION
CHECK .
SELF-DIAGNOSTICS
During vehicle operation, air bag diagnostic monitor detects and stores both intermittent and hard failure codes
in non-volatile memory. The DTCs can be retrieved with the New Generation Star (NGS) tester using the
retrieve/clear continuous codes option. If no DTCs are present, NGS Tester will display SYSTEM PASSED
message. Once a fault code is logged in air bag diagnostic monitor memory, it will stay in memory until 80
ignition cycles have been recorded or until NGS is used to erase the DTCs.
The on-demand self test can be used to verify there are no electrical faults within SRS. During this test air bag
diagnostic monitor will check of each electrical component in system. If fault is detected, DTC is displayed on
to verify operation.
USING NGS TESTER
Page 21
INTEGRATED AIR
to DIAGNOSTIC DATA LINK and press TRIGGER. If results of circuit 70, 914, or 915 is SYSTEM PASSED,
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
1. Connect New Generation Star Tester (007-00500) or equivalent to Data Link Connector (DLC), located
under instrument panel, to retrieve continuous diagnostic trouble codes (DTCs) and run self test
diagnostics. See RETRIEVING FAULT CODES or DATA LINK DIAGNOSTIC TEST .
2. If self test is passed and no DTCs are retrieved, or there is a module communication error, refer to
DIAGNOSTIC SYMPTOMS table. If DTCs are retrieved, see FAULT CODE IDENTIFICATION
table.
RETRIEVING FAULT CODES
1. To retrieve and/or clear DTCs, follow these step: Connect NGS to Data Link Connector (DLC), located
under instrument panel. Turn ignition switch to RUN position. Select MODEL YEAR and VEHICLE.
Select DIAGNOSTIC DATA LINK. Select IABM-INTEGRATED AIR BAG MONITOR. Select
DIAGNOSTIC TEST MODES. Select RETRIEVE/CLEAR CONTINUOUS DTCs.
2. After pressing START, all continuous DTCs will be displayed open screen. Before proceeding with
clearing operation, make note of DTCs displayed. See FAULT CODE IDENTIFICATION table under
DIAGNOSTIC TESTS. Once cleared, DTCs cannot be retrieved.
3. To clear all DTCs, press C ALL. Clearing of individual DTCs (C ONE) is not supported by air bag
diagnostic monitor. The NGS will retrieve DTCs again after clearing DTCs, and if any remain they will
be displayed. Hard DTCs will be redisplayed after clearing DTCs since they cannot be cleared from air
bag diagnostic monitor.
ON-DEMAND SELF-TEST
Connect NGS to data link connector, located under instrument panel. Turn ignition switch to RUN position.
Select MODEL YEAR and VEHICLE. Select DIAGNOSTIC DATA LINK. Select IABMBAG MONITOR. Select DIAGNOSTIC TEST MODES. Select ON-DEMAND SELF TEST. Press START
and then TRIGGER. Air bag diagnostic monitor will run on demand self test and display ON-DEMAND DTCs
on the screen.
DATA LINK DIAGNOSTIC TEST
Connect NGS to data link connector, under instrument panel. Turn ignition switch to RUN position. Rotate dial
the ISO 9141 communication link test has passed (air bag diagnostic monitor). If air bag diagnostic monitor is
listed after results of these circuits, followed by NO RESPONSE/NOT EQUIPPED, test failed, refer to
DIAGNOSTIC SYMPTOMS table.
DIAGNOSTIC SYMPTOMS
Condition Test
Module Communication Error TEST A
No Air Bag Warning Light TEST B
Continuous Air Bag Warning Light TEST C
Rapid Continuous Flashing Air Bag Warning Light TEST D
Data Link Diagnostic Test Failure\Air Bag Diagnostic Monitor Communication Fault TEST E
Page 22
FAULT CODE IDENTIFICATION
Turn ignition switch to OFF position. Deactivate system. See
Right Front Impact Sensor Not Mounted To Vehicle
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fault Code Flash Code Description
B1342 24 Internal Microprocessor Fault On-Demand Self-Test Only)
B1867 12/52 Low Battery Voltage
B1869 -- No Indicator/Inoperative Circuit
B1913 13/53 Air Bag Circuit Shorted To Ground
B1914 14/54 Impact Sensor Short To Ground
B1921 21 Diagnostic Monitor Not Mounted To Vehicle Properly
B1922 22 Safing Sensor Shorted To Battery Voltage
B1924 24 System Disarm Failure Or Internal Diagnostic Monitor Fault
B1932 32 High Resistance Or Open In Driver-Side Air Bag Circuit
B1933 33 High Resistance Or Open In Passenger-Side Air Bag Circuit
B1934 34 Low Resistance Or Short In Driver-Side Air Bag Circuit
B1935 35 Low Resistance Or Short In Passenger-Side Air Bag Circuit
B1941 41 Right Front Impact Sensor Feed/Return Circuit Open
B1942 42 Left Front Impact Sensor Feed/Return Circuit Open
B1944 44
Properly
B1945 45 Left Front Impact Sensor Not Mounted To Vehicle Properly
DIAGNOSTIC TESTS
TEST A - MODULE COMMUNICATION ERROR
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
Perform this test only if condition remains after checking to ensure NGS tester is properly connected to DLC
(check connection for damaged or loose terminals), ignition switch is turned to RUN position, and battery is
properly charged.
Possible Causes
Module communication error might be caused by faulty NGS tester, data link connector (DLC), air bag
diagnostic monitor, or related circuitry.
Test Procedure
1. Check For Ignition Voltage
DISABLING & ACTIVATING AIR
Page 23
BAG SYSTEM
. Disconnect air bag diagnostic monitor. Turn ignition switch to ON position. Measure
. Check fuse No. 2 (10A).
COMMUNICATION FAULT.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
voltage between air bag diagnostic monitor C209-6, circuit 298 (Purple/Orange wire) and ground. If
voltage is greater than 10 volts, go to next step. If voltage is not as specified, repair circuit 298
(Purple/Orange wire) and go to step 6).
2. Check Circuit 549 (Black/Orange) For Open
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor connector. Measure
resistance between air bag diagnostic monitor C209-18, circuit 549 (Black/Orange wire) and ground. If
resistance is less than 5 ohms, go to next step. If resistance is not as specified, repair circuit 549
(Black/Orange wire) and go to step 6).
3. Check For Battery Voltage
Measure voltage between air bag diagnostic monitor C209-14, circuit 937 (Red/White wire) and ground.
If voltage is greater than 10 volts, go to step 6). If voltage is not as specified, go to next step.
4. Check Battery Fuse
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM
If fuse is open, go to next step. If fuse is not OK, repair circuit 937 (Red/White wire) and go to next step
6).
WARNING: Certain fault conditions (DTC B1913 or B1914) may cause air bag
diagnostic monitor to intentionally open fuse No. 2 (10A) to disarm
SRS. DO NOT substitute another fuse value for 10A fuse. Any other
fuse value may cause future disarming failure and danger to
occupants of vehicle. Once air bag diagnostic monitor has disarmed
SRS, it will not attempt to do so again until appropriate fault code
(DTC B1913 or B1914) has been cleared. Do not reactivate system
until all fault codes have been repaired and cleared.
5. Check For Short In Harness
Replace open fuse. If fuse does not open again, go to next step. If fuse opens again, repair circuit 937
(Red/White wire) and go to next step.
6. Check Module Communication
Turn ignition switch to OFF position. Reconnect system components. Turn ignition switch to ON
position. If air bag diagnostic monitor communicates, reactivate system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning light for proper system function. See
SYSTEM OPERATION CHECK . If air bag diagnostic monitor does not communicate, go to TEST E
- DATA LINK DIAGNOSTIC TEST FAILURE/AIR BAG DIAGNOSTIC MONITOR
Page 24
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Fig. 10: Air Bag Diagnostic Monitor Connector Terminal ID
Courtesy of FORD MOTOR CO.
TEST B/DTC B1869 - NO AIR BAG WARNING LIGHT
Page 25
Turn ignition switch to ON position. Connect jumper wire from terminal C208
-
11, circuit 608
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The AIR BAG warning light is designed to light for 4-8 seconds when ignition switch is turned to ON position.
This initial 4-8 seconds is normal operation for warning light, indicating SRS is functioning properly. If there is
an open in circuit C208-11, circuit 608 (Black/Yellow wire), the air bag warning light will not light.
If air bag diagnostic monitor detects open in AIR BAG warning light circuit and another fault in system exists,
the tone generator in diagnostic monitor will activate and five sets of five beeps will occur every 30 minutes
while ignition switch is in ON position. The beeps do not indicate Code 55 or any other code. The air bag
warning light circuitry must be repaired before DTCs can be retrieved.
The air bag diagnostic monitor requires power at terminal C209-6, circuit 298 (Purple/Orange wire) to charge
AIR BAG warning light circuit properly. If there is an open in light circuit at terminal C208-11, circuit 608
(Black/Yellow wire), the AIR BAG warning light will not light.
Possible Causes
An inoperative AIR BAG warning light may be caused by a burned out bulb or open wiring in air bag warning
light circuit.
Test Procedure
1. Understand Function
Read description for this test and examine wiring diagram for schematic. See WIRING DIAGRAM . If
DTC operation is well understood, go to next step. If not, re-examine description and schematic.
2. Check For Other Warning Indicators
Turn ignition switch to ON position. If any other warning lights on instrument cluster are inoperative,
check instrument cluster. If no other warning lights are inoperative, go to next step.
3. Check Supply To Air Bag Diagnostic Monitor
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Disconnect air bag
diagnostic monitor connectors. Measure resistance between air bag diagnostic monitor C208-11, circuit
608 (Black/Yellow wire) and instrument cluster C238-6, circuit 608 (Black/Yellow wire). If resistance is
less than 5 ohms, check circuit 650 (Black/Light Blue for open. If not, check air bag indicator for
operation.
4. Check Bulb Operation
Page 26
(Black/Yellow wire) to ground. If AIR BAG warning light comes on, replace air bag diagnostic monitor.
system. If warning light does not come on, repair circuit 608 (Black/Yellow wire). Reactivate system. See
reactivate system. See
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect and reactivate
DISABLING & ACTIVATING AIR BAG SYSTEM .
TEST C - CONTINUOUS AIR BAG WARNING LIGHT
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The AIR BAG warning light is designed to light for 4-8 seconds when ignition switch is turned to ON position.
This initial 4-8 seconds is normal operation for warning light, indicating SRS is functioning properly. The air
bag diagnostic monitor incorporates a solid state circuit which shorts air bag warning light line, circuit 608
(Black/Yellow wire), to ground to turn on AIR BAG warning light. When Black diagnostic monitor harness
connector C208 is disconnected from air bag diagnostic monitor, a shorting bar within harness connector shorts
terminal C208-11, circuit 608 (Black/Yellow wire) and C208-10, circuit 650 (Black/Light Blue wire) together,
causing continuous AIR BAG warning light.
The air bag diagnostic monitor requires power at terminal C209-6, circuit 298 (Purple/Orange wire) to charge
AIR BAG warning light circuit properly. Loss of ignition voltage at this terminal due to an open circuit or short
to ground will result in continuous air bag warning light, due to ignition voltage applied to terminal C208-19,
circuit 1044 (White/Yellow wire).
Possible Causes
Continuous AIR BAG warning light may be caused by a DTC which has flashed five times after ignition was
turned to ON and has timed out, a disconnected, poorly connected, or damaged air bag diagnostic monitor,
shorted air bag warning light wiring, or loss of ignition voltage at terminal C209-6, circuit 298 (Purple/Orange
wire) of air bag diagnostic monitor.
Test Procedure
1. Understand Function
Read description for this test and examine wiring diagram for schematic. See WIRING DIAGRAM . If
DTC operation is well understood, go to next step. If not, re-examine description and schematic.
2. Check Circuit 608 (Black/Yellow) For Short To Ground
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor connectors. Remove plastic
locking wedge from connector C208. Turn ignition switch to ON position. If AIR BAG warning light is
not on, go to next step. If warning light is on, repair circuit 608 (Black/Yellow wire). Reconnect and
DISABLING & ACTIVATING AIR BAG SYSTEM
Page 27
sensors are disconnected the air bag diagnostic monitor will store DTCs B1941, B1942, B1944, B1945, and any
COMMUNICATION FAULT
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
3. Check For Short To Battery Voltage
Turn ignition switch to OFF position. Measure voltage between air bag diagnostic monitor C209-6,
circuit 298 (Purple/Orange wire) and ground. If voltage is less than 1 volt, go to next step. If voltage is
not as specified, repair circuit 298 (Purple/Orange wire) for short to B+. Check for aftermarket circuit
attachments. Reconnect and reactivate system. See DISABLING & ACTIVATING AIR BAG
SYSTEM .
4. Inspect Shorting Bars
Inspect shorting bars on plastic locking wedge for damage or poor connection. If shorting bars are in
good condition, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR under REMOVAL
& INSTALLATION. Reconnect, verify, and reactivate system. If shorting bars are not in good condition,
replace plastic locking wedge. Reconnect, verify, and reactivate system. See DISABLING &
ACTIVATING AIR BAG SYSTEM .
TEST D - RAPID CONTINUOUS FLASHING AIR BAG WARNING LIGHT/ ALL FRONT IMPACT
SENSORS DISCONNECTED
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
An air bag diagnostic monitor which has yet to be powered up in an electrically complete system will remain in
assembly plant mode until it is powered up in good system for period of time. While air bag diagnostic monitor
is in assembly plant mode: if both front impact sensors are disconnected, the diagnostic monitor will flash AIR
BAG warning light continuously at rapid rate; if fault exists in system, DTC will flash on warning light but will
not be stored in memory. When air bag diagnostic monitor is not in assembly plant mode: if both front impact
other applicable fault code.
Possible Causes
Rapid continuous flashing AIR BAG warning light may be caused by both front impact sensors are
disconnected from wiring harness, or main wiring harness is not connected to engine compartment wiring
harness.
Test Procedure
Reference To DTCs
To diagnose and repair this condition refer to DTCs B1941, B1942, B1944, or B1945.
TEST E - DATA LINK DIAGNOSTIC TEST FAILURE/AIR BAG DIAGNOSTIC MONITOR
Page 28
Module Communication Error must be performed to verify power and ground to suspect module before
SYSTEM OPERATION
tests every time ignition switch is turned to ON position. If
microprocessor fault exists in air bag diagnostic monitor. DTC B1924 is retrieved like any other DTC and
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
Test A performing the following test. Do not perform test unless instructed. This test assumes a fault has been detected
in system with direction to enter a specific diagnostic routine. Performing this test without direction may
produce incorrect results and replacement of working components. Correct test results are dependent on proper
operation of related components and systems.
Possible Causes
Data link test failure due to air bag diagnostic monitor communication fault may be caused by a faulty
diagnostic monitor, data link connector, or circuits on applicable wiring.
Test Procedure
Check Resistance Between DLC And Diagnostic Monitor C208
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor connector C208. Inspect
diagnostic monitor C208 and data link connector C228 for damage. Measure resistance from terminal
C208-12, circuit 70 (Light Blue/White wire) to DLC connector terminal C228-7. If connectors are OK
and resistance is less than 5 ohms, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR
under REMOVAL & INSTALLATION. Test system for normal operation. See
CHECK . If resistance is not as specified, repair connectors and/or repair circuit 70 (Light Blue/White
wire). Test system for normal operation.
DTC B1342/B1924 - SYSTEM DISARM FAILURE/INTERNAL DIAGNOSTIC MONITOR FAULT
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
When air bag diagnostic monitor detects DTC B1342 or B1924, it attempts to disarm SRS to prevent
inadvertent air bag deployment by opening fuse No. 2 (10A) feeding air bag diagnostic monitor terminals C20913 and C209-14. It attempts to open fuse No. 2 (10A) by activating an internal solid state switch which shorts
battery feed at terminal C209-13 to sheet metal ground at air bag diagnostic monitor bracket.
The air bag diagnostic monitor performs several selfany of these tests fail, AIR BAG warning light will flash Code 24. If conditions resume normal operation, DTC
B1924 will be stored in memory. The failure will either set DTC B1342 or B1924, depending on cause of
failure. DTC B1342 can only be retrieved by running ON-DEMAND SELF-TEST and indicates an internal
Page 29
indicates other diagnostic monitor faults.
24, circuit 624 (Yellow/White wire) (right). If resistance readings are infinite (open), go to step
reactivate system. See
DISABLING & ACTIVATING AIR BAG SYSTEM
. Go to step 14).
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Possible Causes
System disarm failure or internal diagnostic failure can be caused by an improper fuse value at terminal C20913 and C209-14, or excessive resistance or opens in battery feed circuit or C209-13 due to damaged wiring.
This fault can also be caused by vehicle charging system problem, internal air bag diagnostic monitor failure on
diagnostic or system disarm, or resistance to ground in normally open front impact sensor circuits 617
(Pink/Orange wire), 619 (Pink/White wire), 624 (Yellow/White wire), and 625 (Yellow/Light Green wire).
Test Procedure
1. Check For Hard Or Intermittent DTC
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1342/B1924 is retrieved,
fault is hard, go to next step. If DTC B1342 is not retrieved, fault is intermittent, go to step 7).
2. Check For Module Failure
Using results from step 1), if self test did not respond with DTC B1342, go to next step. If self test did
respond with DTC B1342, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR under
REMOVAL & INSTALLATION. Reconnect, verify, and reactivate system. See DISABLING &
ACTIVATING AIR BAG SYSTEM . Go to step 14).
3. Check Primary Sensor Feed
Turn ignition switch to OFF position. Deactivate system. See DISABLING & ACTIVATING AIR
BAG SYSTEM . Disconnect air bag diagnostic monitor. Measure resistance between air bag diagnostic
monitor C209-18, circuit 549 (Black/Orange wire) and C209-15, circuit 619 (Pink/White wire) (left),
C209-16, circuit 617 (Pink/Orange wire) (right), C208-23, circuit 625 (Yellow/Light Green wire) (left),
and C208-
6). If resistance is not as specified, go to next step.
4. Determine If Sensor Or Wire Is Shorted
Disconnect suspect primary crash sensor found in step 3). Measure resistance between suspect front
impact sensor terminals No. 2 and 4. If resistance reading is infinite (open), go to next step. If resistance
is not as specified, replace front impact sensor. See FRONT IMPACT SENSORS under REMOVAL &
INSTALLATION. Reconnect system. Go to step 14).
5. Check For Shorted Sensor Circuit
Measure resistance between air bag diagnostic monitor C209-15, circuit 619 (Pink/White wire) and
ground. If resistance is greater than 10 Kohms, repair circuit 625 (Yellow/Light Green wire) or 624
(Yellow/White wire). Reconnect, verify, and reactivate system. Go to step 14). If resistance is not as
specified, repair circuit 619 (Pink/White wire) or 617 (Pink/Orange wire). Reconnect, verify, and
Page 30
DEMAND
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
6. Check For Incorrect Wiring
Examine air bag diagnostic monitor harness connector C208-22. This terminal should not be used. If a
wire is connected at terminal C208-22, correct improper wiring and reconnect air bag diagnostic monitor.
Go to step 14). If a wire is not connected at terminal C208-22, replace air bag diagnostic monitor. See
DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect, verify, and reactivate
system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 14).
7. Check For Serviced DTCs
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1342/B1924 was retrieved, go to next step. If DTC B1342/B1924 was not
retrieved, go to step 14).
8. Check Front Impact Sensor Circuits
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Measure resistance between
air bag diagnostic monitor C209-18, circuit 549 (Black/Orange wire) and C209-15, circuit 619
(Pink/White wire) (left), C209-16, circuit 617 (Pink/Orange wire) (right), C208-23, circuit 625
(Yellow/Light Green wire) (left), and C208-24, circuit 624 (Yellow/White wire) (right). If resistance
readings are infinite (open), go to step 11). If resistance is not as specified, go to next step.
9. Identify Shorted Circuit
Disconnect suspect primary crash sensor found in step 8). Measure resistance between suspect front
impact sensor terminals No. 2 and 4. If resistance reading is infinite (open), go to next step. If resistance
is not as specified, replace front impact sensor. See FRONT IMPACT SENSORS under REMOVAL &
INSTALLATION. Reconnect system. Go to step 14).
10. Check Sensor Circuits
Measure resistance between air bag diagnostic monitor C209-15, circuit 619 (Pink/White wire) and
ground. If resistance is greater than 10 Kohms, repair circuit 625 (Yellow/Light Green wire) or 624
(Yellow/White wire). Reconnect, verify, and reactivate system. Go to step 14). If resistance is not as
specified, repair circuit 619 (Pink/White wire) or 617 (Pink/Orange wire). Reconnect, verify, and
reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 14).
11. Confirm Battery Connection
Turn ignition switch to OFF position. Measure resistance between air bag diagnostic monitor C209-13,
circuit 937 (Red/White wire) and C209-18, circuit 549 (Black/Orange wire). If voltage is greater than 10
volts, go to next step. If voltage is not as specified, repair circuit 937 and reconnect diagnostic monitor.
Go to step 14).
WARNING: Certain fault conditions (DTC B1913 or B1914) may cause air bag
diagnostic monitor to intentionally open fuse No. 2 (10A) to disarm
SRS. DO NOT substitute another fuse value for 10A fuse. Any other
Page 31
(Red/White) drops below 8 volts, diagnostic monitor will flash Code 12 on AIR BAG warning light.
14, circuit 937 (Red/White) may be caused by an open
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
fuse value may cause future disarming failure and danger to
occupants of vehicle. Once air bag diagnostic monitor has disarmed
SRS, it will not attempt to do so again until appropriate fault code
(DTC B1913 or B1914) has been cleared. Do not reactivate system
until all fault codes have been repaired and cleared.
12. Check Fuse No. 2 (10A)
Ensure fuse No. 2 (10A), located in power distribution box, is correct value (10A). If fuse is correct
value, go to next step. If fuse is not correct value, replace fuse No. 2 with correct fuse value (10A). Do
not use substitutions. Reconnect air bag diagnostic monitor connectors and go to step 14).
13. Check For Short To Power
Turn ignition switch to OFF position. Measure voltage between air bag diagnostic monitor C209-13,
circuit 937 (Red/White wire) and C209-18, circuit 549 (Black/Orange wire). If voltage is zero volts,
replace fuse No. 2 (10A). Do not use substitutions. Replace air bag diagnostic monitor. See
DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect and reactivate system.
Go to next step. If voltage is not as specified, repair circuit 937 and reconnect air bag diagnostic monitor
connectors. Go to next step.
14. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1867 - LOW BATTERY VOLTAGE
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures voltage at terminal C209-14, circuit 937 (Red/White) of air bag
diagnostic monitor connector. Voltage at this terminal should be equal to battery voltage. If voltage at C209-14,
circuit 937
If voltage at this terminal drops below 5 volts, DTC B1867 will be stored in memory. If the loss of battery
voltage at terminal C209-14, circuit 937 (Red/White) is intermittent or repaired, air bag diagnostic monitor will
flash Code 52 (or higher priority code if exists) on next ignition cycle.
Possible Causes
Low voltage at air bag diagnostic monitor terminal C209in battery circuit, a short to ground on battery feed circuit, or a problem in charging system.
Page 32
DISABLING &
7.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
1. Check For Hard Or Intermittent DTC
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1867 is retrieved, go to
next step. If DTC B1867 is not retrieved, go to step 7).
2. Check Power Supply
Connect NGS to DLC. Select IABM. Select Pid/Data Monitor and Record. Select Pid VBATIAB. If
voltage is less than 5 volts, go to step 4). If voltage is not as specified, go to next step.
3. Check Charging System
Measure charging system voltage. If voltage is more than 9 volts, deactivate system. See
ACTIVATING AIR BAG SYSTEM . Replace air bag diagnostic monitor. See DIAGNOSTIC
MONITOR under REMOVAL & INSTALLATION. Reconnect, verify, and reactivate system. Go to
step 10). If voltage is not as specified, repair charging system. Go to step 10).
4. Check Fuse No. 2 (10A)
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Disconnect air bag
diagnostic monitor connectors. Check fuse No. 2 (10A) in fuse junction panel. If fuse is OK, go to next
step. If fuse is not OK, repair circuit 937 (Red/White wire). Connect diagnostic monitor. Go to step 10).
WARNING: Certain fault conditions (DTC B1913 or B1914) may cause air bag
diagnostic monitor to intentionally open fuse No. 2 (10A) to disarm
SRS. DO NOT substitute another fuse value for 10A fuse. Any other
fuse value may cause future disarming failure and danger to
occupants of vehicle. Once air bag diagnostic monitor has disarmed
SRS, it will not attempt to do so again until appropriate fault code
(DTC B1913 or B1914) has been cleared. Do not reactivate system
until all fault codes have been repaired and cleared.
5. Check Circuit 937 (Red/White wire) For Short To Ground
Replace open fuse No. 2 (10A). Do not use any substitutions. If fuse does not blow, go to next step. If
fuse opens again, repair short to ground on circuit 937 (Red/White wire). Connect air bag diagnostic
monitor. Go to step 10).
6. Confirm Condition
Reconnect air bag diagnostic monitor connectors. If fuse does not open, go to step 10). If fuse opens,
replace diagnostic monitor. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION.
Replace fuse No. 2 (10A). Do not use substitutions. Reconnect and reactivate system. See DISABLING
& ACTIVATING AIR BAG SYSTEM . Go to step 10).
Check If repaired
Page 33
DEMAND
repair problem. Check fuse No. 2 (10A) for correct value. Go to step 10). If there is not a charging system
13
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ONSELF-TEST . If DTC B1867 was retrieved, check fuse No. 2 (10A) for correct value. Go to step 10). If
DTC B1867 was not retrieved, go to next step.
8. Check Charging System
An intermittent charging system problem could cause DTC B1867. If there is a charging system problem,
problem, go to next step.
9. Check Battery Feed
Inspect all crimps, terminals, fuses, wires, etc. in circuit 937 (Red/White wire) feeding terminals C209and C209-14 of air bag diagnostic monitor. See Fig. 5 . Look for poor connections, etc. If problems are
noted, repair circuit 937, check fuse No. 2 (10A) for correct value and go to step 10). If no problems are
noted, recheck fault code. Look for causes of intermittent low battery voltage at terminal C209-13 circuit
937 (Red/White wire). See Fig. 5 . Attempt to recreate hard faults by driving vehicle, flexing wiring
harnesses, etc. Correct intermittent fault and go to step 10).
10. Check For Other DTCs
Connect NGS to DLC. Perform ON-DEMAND SELF-TEST . If other DTCs are retrieved go to proper
DTC test. If no other DTCs are retrieved, reactivate system and clear all DTCs. See DISABLING &
ACTIVATING AIR BAG SYSTEM .
DTC B1913 - AIR BAG CIRCUIT SHORT TO GROUND
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures voltage at terminal C209-2, C209-3, C209-4, and C209-5 of air bag
diagnostic monitor connector. Voltage at these terminals are set by diagnostic monitor and vary with charging
system voltage. If air bag diagnostic monitor detects low voltage at any of these terminals, DTC B1913 will be
stored in memory and AIR BAG warning light will flash Code 13 to indicate possible short to ground on these
circuits.
At the same time air bag diagnostic monitor begins flashing Code 13, it attempts to disarm SRS to prevent
inadvertent air bag deployment by opening fuse No. 2 (10A) feeding air bag diagnostic monitor terminal C20913 and C209-14. It attempts to open fuse by activating solid state switch which shorts battery feed at terminal
C209-13, circuit 937 (Red/White) to sheet metal ground at air bag diagnostic monitor bracket.
VOLTAGE SPECIFICATIONS
Page 34
to ground in either of front impact sensors. Low voltage at specified terminals may also be caused by an internal
side air
next step. If DTC B1913 was not retrieved, replace PAD switch and go to step 19).
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Voltage At Terminal C209-2, C209-3, C209-4 or C209-5 System Voltage
1.5 9.0
1.6 9.5
1.7 10.0
1.8 10.5
1.9 11.0
2.0 11.5
2.1 12.0
2.2 12.5
2.3 13.0
2.4 13.5
2.5 14.0
2.6 14.5
2.7 15.0
2.8 15.5
2.9 16.0
Possible Causes
Low voltage at air bag diagnostic monitor terminal C209-2, C209-3, C209-4, or C209-5 may be caused by a
short to ground on circuits 607 (Light Blue/Orange wire), 614 (Gray/Orange wire), 615 (Gray/White wire), 616
(Pink/Black wire), or 1112 (White/Light Blue wire), or by resistance to ground on circuits 617 (Pink/Orange
wire), 619 (Pink/White wire), 624 (Yellow/White wire), 625 (Yellow/Light Green wire), or internal resistance
short to ground within air bag clockspring, or an internal short to ground within driver-side or passengerbag module.
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1913 is retrieved, go to
next step. If DTC B1913 is not retrieved, go to step 13).
2. Check Passenger-Side Air Bag Deactivation Switch Position
Ensure passenger-side air bag deactivation (PAD) switch is in ON position. If the PAD switch is in ON
position, go to step 4). If PAD switch is not in ON position, turn switch to ON position and go to next
step.
3. Recheck System
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1913 was retrieved, go to
Page 35
. If DTC B1913 was retrieved, go
connector at base of steering column for damaged, chafed or pinched wires. Repair as necessary. Measure
circuit 650 (Black/Orange wire). If resistance is less than 10 Kohms, go to next step. If resistance is not as
is not as specified, repair circuit 1112 (White/Light Blue wire) or 1113 (Yellow/Light Green wire) and go
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
4. Check For Shorted Air Bag
Turn ignition switch to OFF position. Deactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Carefully disconnect air bag modules during deactivation. Turn ignition switch to ON
position. Connect NGS to DLC. Perform ON-DEMAND SELF-TEST
to next step. If DTC B1913 was not retrieved, go to step 12).
5. Check Driver-Side Air Bag Circuit
Turn ignition switch to OFF position. Disconnect diagnostic monitor. Inspect clockspring wiring harness
resistance between air bag diagnostic monitor C209-2, circuit 614 (Gray/Orange wire) and C209-18,
specified, go to step 7).
6. Check Circuit 614 For Short To Ground
Disconnect clockspring connector at base of steering column. Measure resistance between air bag
diagnostic monitor C209-2, circuit 614 (Gray/Orange wire). If resistance is greater than 10 Kohms,
replace clockspring. See CLOCKSPRING under REMOVAL & INSTALLATION. Reconnect, verify,
and reactivate system. Go to step 19). If resistance is not as specified, repair circuit 614 or 615.
Reconnect, verify, and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Go to step 19).
7. Check Passenger-Side Air Bag Module Circuits For Short
Examine passenger-side air bag module wiring harness connector. Check for pinched or chafed wires.
Ensure PAD switch is in ON position. Measure resistance between air bag diagnostic monitor C209-5,
circuit 1112 (White/Light Blue wire) and C209-18, circuit 549 (Black/Orange wire). If resistance is
greater than 10 Kohms, go to step 11). If resistance is not as specified, go to next step.
8. Check Circuit 1112 And 1113 For Short To Ground
Disconnect PAD switch connector C213. Measure resistance between PAD switch C213-3, circuit 1112
(White/Light Blue wire) and ground. If resistance is greater than 10 Kohms, go to next step. If resistance
to step 19).
9. Check Circuit 607 And 616 For A Short To Ground
Disconnect PAD switch connector C214. Measure resistance between PAD switch C214-1, circuit 607
(Light Blue/Orange wire) and ground. If resistance is greater than 10 Kohms, replace PAD switch and go
to step 19). See PAD SWITCH under REMOVAL & INSTALLATION. If resistance is not as specified,
go to next step.
10. Check Circuit 607 For A Short To Ground
Page 36
Disconnect passenger
-
side Air Bag Simulator (105
-
00010). Measure resistance between PAD switch
16,
under REMOVAL & INSTALLATION. Reconnect, verify, and
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
C214-1, circuit 607 (Light Blue/Orange wire) and ground. If resistance is greater than 10 Kohms, repair
circuit 616 (Pink/Black wire) and go to step 19). If resistance is not as specified, repair circuit 607 (Light
Blue/Orange wire) and go to step 19).
11. Check Front Impact Sensors
Measure resistance between air bag diagnostic monitor C209-15, circuit 619 (Pink/White wire) and
ground, and between air bag diagnostic monitor C209-16, circuit 617 (Pink/Orange wire) and ground. If
resistance readings are less than 10 Kohms, go to next step. If resistance is not as specified, replace
diagnostic monitor. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION.
Reconnect, verify, and reactivate system. Go to step 19).
12. Check For Shorted Front Impact Sensor
Turn ignition switch to OFF position. Disconnect right and left front impact sensor connectors. Check
suspect impact sensor found in step 11). Measure resistance between air bag diagnostic monitor C209circuit 617 (Pink/Orange wire) and C208-21, circuit 618 (Purple/Light Green wire), for right front impact
sensor. Measure resistance between air bag diagnostic monitor C209-15, circuit 619 (Pink/White wire)
and C208-20, circuit 620 (Purple/Light Blue wire), for left front impact sensor. If resistance is less than
10 Kohms, go to next step. If resistance is not as specified, replace front impact sensor in question. See
FRONT IMPACT SENSORS under REMOVAL & INSTALLATION. Reconnect, verify, and
reactivate system. Go to step 19).
13. Check For Shorted Front Impact Sensor Circuit
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor connectors. Measure
resistance between air bag diagnostic monitor C209-15, circuit 619 (Pink/White wire) and ground (left
sensor), or between C209-16, circuit 617 (Pink/Orange wire) and ground (right sensor). If resistance is
greater than 10 Kohms, repair circuit 625 (Yellow/Light Green wire) (left sensor) or 624 (Yellow/White
wire) (right sensor). Reconnect, verify, and reactivate system. Go to step 19). If resistance is not as
specified, repair circuit 619 (Pink/White wire) (left sensor) or 617 (Pink/Orange wire) (right sensor).
Reconnect, verify, and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Go to step 19).
WARNING: Use a hand held digital multimeter with less than 10MA short circuit
current on the lowest resistance scale possible (200 ohm setting).
Failure to use a meter of this type may cause personal injury due to
air bag deployment.
14. Determine Which Bag is Shorted
Inspect wiring and connector where clockspring mates to main vehicle harness under steering column.
Check for pinched or chafed wires. Make sure shorting bar is properly installed in passenger side air bag
connector. Measure resistance between either of the terminals in passenger-side air bag connector and
metal case of air bag module. If resistance is infinite (open), replace driver-side air bag module. See
DRIVER-SIDE AIR BAG MODULE
Page 37
reactivate system. Go to step 19). If resistance is not as specified, replace passenger
-
side air bag module.
. If DTC B1913 was retrieved, check fuse No. 2 (10A) for correct value and go to step 19). If DTC
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
See PASSENGER-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION. Reconnect,
verify, and reactivate system. Go to step 19).
15. Check For DTC Service
Reactivate system. See COMPLETE SYSTEM DEACTIVATION . Perform ON-DEMAND SELF-
TEST
B1913 was not retrieved, deactivate system and go to next step.
16. Check For Intermittent Shorts
Inspect circuits 614 (Gray/Orange wire), 615 (Gray/White wire), 607 (Light Blue/Orange wire), 616
(Pink/Black wire), 1112 (White/Light Blue wire), and 1113 (Yellow/Light Green wire) for pinched or
chafed wires or other problems. If problems are noted, repair wiring, check fuse No. 2 (10A) for correct
value. Reconnect, verify, and reactivate system. Go to step 19). If no problems are noted, go to next step.
17. Check Clockspring And Air Bag Modules
Inspect clockspring wiring at harness connector. Inspect steering wheel hub where clockspring mates to
driver-side air bag connector. Inspect wiring where passenger-side air bag module mates to harness
connector. If any problems are noted, repair problem, check fuse No. 2 (10A) for correct value.
Reconnect, verify, and reactivate system. Go to step 19). If no problems are noted, go to next step.
18. Check Front Impact Sensors
Inspect front impact sensors and associated circuits 617 (Pink/Orange wire), 624 (Yellow/White wire),
619 (Pink/White wire), and 625 (Yellow/Light Green wire). Look for signs of corrosion or resistance to
ground. If problems are noted, replace front impact sensor and check fuse No. 2 (10A) for correct value.
See FRONT IMPACT SENSORS under REMOVAL & INSTALLATION. Reconnect, verify, and
reactivate system. Go to next step. If no problems are noted, re-examine fault code and check for causes
of intermittent shorts or resistance to ground. Attempt to recreate hard faults by driving vehicle, flexing
wiring harnesses, etc. Repair intermittent problems and go to next step.
19. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1914 - FRONT IMPACT SENSOR SHORTED TO GROUND
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
Page 38
The air bag diagnostic monitor measures voltage at terminal C208
-
23, circuit 625 (Yellow/Light Green wire)
1.
fuse. Substituting any other fuse value may cause future disarming failure
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
and C208-24, circuit 624 (Yellow/White wire) of air bag diagnostic monitor connector. Voltage at these
terminals are set by diagnostic monitor and vary with charging system voltage. If air bag diagnostic monitor
detects low voltage at either of these terminals, DTC B1914 will be stored in memory and AIR BAG warning
light will flash Code 14 to indicate possible short to ground on these circuits.
At the same time air bag diagnostic monitor begins flashing Code 13, it attempts to disarm SRS to prevent
inadvertent air bag deployment by opening fuse No. 2 (10A) feeding air bag diagnostic monitor terminal C20913, circuit 937 (Red/White) and C209-14, circuit 937 (Red/White). It attempts to open fuse by activating solid
state switch which shorts battery feed at terminal C209-13, circuit 937 (Red/White) to sheet metal ground at air
bag diagnostic monitor bracket.
VOLTAGE SPECIFICATIONS
Voltage At Terminal C208-23 & C208-24 System Voltage
8.6 9.0
9.1 9.5
9.6 10.0
10.1 10.5
10.6 11.0
11.1 11.5
11.6 12.0
12.1 12.5
12.6 13.0
13.1 13.5
13.6 14.0
14.1 14.5
14.6 15.0
15.1 15.5
15.6 16.0
WARNING: Certain fault conditions may cause diagnostic monitor to intentionally
blow AIR BAG fuse. DO NOT use any other fuse value except a 10-amp
and may result in danger to vehicle occupants.
Possible Causes
Low voltage at air bag diagnostic monitor terminal C208-23, C209-15, C209-16, or C208-24 may be caused by
a short to ground on circuits 617 (Pink/Orange wire), 619 (Pink/White wire), 624 (Yellow/White wire), 625
(Yellow/Light Green wire), or internal short to case ground within either of front impact sensors.
Test Procedure
Verify Condition
Page 39
under REMOVAL &
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1914 is retrieved, go to
next step. If DTC B1914 is not retrieved, go to step 5).
2. Identify Shorted Circuit
Deactivate air bag system. See COMPLETE SYSTEM DEACTIVATION under DISABLING &
ACTIVATING AIR BAG SYSTEM. Disconnect diagnostic monitor. Using an multimeter set to
200k/ohm scale or Auto, measure resistance between terminal C209-18, circuit 549 (Black/Orange wire)
of air bag diagnostic monitor and terminal C209-15, circuit 619 (Pink/White wire) and C208-23, circuit
625 (Yellow/Light Green wire) of left front impact sensor, and terminal C209-16, circuit 617
(Pink/Orange wire) and C208-24, circuit 624 (Yellow/White wire) of right front impact sensor. If one or
more resistance reading is not infinite, go to next step. If all resistance readings are infinite (open),
replace diagnostic monitor. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION.
Reconnect, verify, and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
3. Determine If Sensor Or Wire Is Shorted
Disconnect impact sensor where resistance reading was not infinite in step 2). Measure resistance
between air bag diagnostic monitor C209-16, circuit 617 (Pink/Orange wire) and C208-21, circuit 618
(Purple/Light Green wire), for right front impact sensor. Measure resistance between air bag diagnostic
monitor C209-15, circuit 619 (Pink/White wire) and C208-20, circuit 620 (Purple/Light Blue wire), for
left front impact sensor. If resistance reading is infinite (open), go to next step. If resistance reading is not
infinite, replace front impact sensor in question. See FRONT IMPACT SENSORS
INSTALLATION. Reconnect system and go to step 7).
4. Check For Shorted Sensor Circuit
Disconnect suspected front impact sensor. Measure resistance between ground and terminal C209-15,
circuit 619 (Pink/White wire) and C208-23, circuit 625 (Yellow/Light Green wire) of left front impact
sensor, and terminal C209-16, circuit 617 (Pink/Orange wire) and C208-24, circuit 624 (Yellow/White
wire) of right front impact sensor. If resistance is greater than 10 Kohms, repair short between circuit 619
(Pink/White wire) or 625 (Yellow/Light Green wire) and circuit 620 (Purple/Light Blue wire) for left
sensor, or between circuit 617 (Pink/Orange wire) or 624 (Yellow/White wire) and circuit 618
(Purple/Light Green wire) for right sensor. Reconnect, verify, and reactivate system. Go to step 7). If
resistance is not as specified, repair circuit 619 (Pink/White wire) or 625 (Yellow/Light Green wire) for
left sensor, or 617 (Pink/Orange wire), or 624 (Yellow/White wire) for right sensor. Reconnect, verify,
and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 7).
5. Check For DTC Service
Deactivate system. See COMPLETE SYSTEM DEACTIVATION . Perform ON-DEMAND SELF-
TEST . If DTC B1914 was retrieved, go to next step. If DTC B1914 was not retrieved, check fuse No. 2
(10A) for correct value and go to step 7).
6. Check Front Impact Sensors
Page 40
Inspect circuits 617 (Pink/Orange wire), 624 (Yellow/White wire), 619 (Pink/White wire) and 625
front impact sensor and repair wiring problems. Check fuse No. 2 (10A) for correct value, go to next step.
. Remove air bag diagnostic monitor and bracket. See
under
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
(Yellow/Light Green wire) for pinched or chafed wires or other problems. If problems are noted, replace
If no problems are noted, reexamine fault code and look for causes of intermittent shorts or resistance to
ground. Attempt to recreate hard faults by driving vehicle, flexing wiring harnesses, etc. Repair
intermittent problems and go to next step.
7. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1921 - DIAGNOSTIC MONITOR NOT MOUNTED TO VEHICLE PROPERLY/GROUND
CIRCUIT OPEN
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures resistance between ground connection at its bracket and reference
ground at terminal C209-18, circuit 549 (Black/Orange wire). If air bag diagnostic monitor measures difference
of more than 3.0 ohms between ground at terminal C209-18, circuit 549 (Black/Orange wire) and the ground at
its bracket, the air bag diagnostic monitor will store DTC B1921 in memory and AIR BAG warning light will
flash Code 21. If condition is repaired or corrected, air bag diagnostic monitor will store DTC B1921 in
memory.
Possible Causes
A high resistance reading at air bag diagnostic monitor bracket ground can be caused by a poor attachment of
air bag diagnostic monitor due to loose mounting, dirt, corrosion, or a poor reference ground at terminal C20810, circuit 650 (Black/Light Blue wire) and C209-18, circuit 549 (Black/Orange wire) of air bag diagnostic
monitor.
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1921 is retrieved, go to
next step. If DTC B1921 is not retrieved, go to step 5).
2. Measure Resistance
Connect NGS to DLC. Select IABM. Select PID/Data Monitor and Record. Select PID BRACKET. If
resistance is more than 5 ohms, deactivate system. See DISABLING & ACTIVATING AIR BAG
SYSTEM
DIAGNOSTIC MONITOR
Page 41
REMOVAL & INSTALLATION. Thoroughly clean mounting surfaces. Reinstall air bag diagnostic
10 circuit 650 (Black/Light Blue wire) feeding diagnostic monitor C208. If poor
connections are noted, repair circuit as necessary. Add ground strap from circuit 549 (Black/Orange wire)
DEMAND
10 circuit 650 (Black/Light Blue wire) feeding diagnostic monitor C208. If poor
reactivate system and clear all DTCs. See
DISABLING & ACTIVATING AIR BAG SYSTEM
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
monitor and go to next step. If resistance is less than 5 ohms, go to step 4).
3. Recheck Resistance
Repeat procedure in step 2). If resistance is greater than 5 ohms, go to next step. If resistance is not as
specified, install air bag diagnostic monitor. Go to step 8).
4. Check Reference Ground
Check attachment of ground connections in C209-18 circuit 549 (Black/Orange wire) feeding diagnostic
monitor C209, and C208-
or 650 (Black/Light Blue wire) to one of the air bag diagnostic monitor mounting fasteners. Reinstall air
bag diagnostic monitor and go to step 8). If no poor connections are noted, replace air bag diagnostic
monitor. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect, verify,
and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 8).
5. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1921 was retrieved, go to next step. If DTC B1921 was not retrieved, go to step
8).
6. Check For Bracket Corrosion
Inspect diagnostic monitor bracket and mounting surfaces. Look for signs of corrosion or poor contact. If
there is no corrosion, go to next step. If significant corrosion is found, replace air bag diagnostic monitor.
See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Verify and reactivate system.
See DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 8).
7. Check Circuit 549 And 650
Check attachment of ground connections in C209-18 circuit 549 (Black/Orange wire) feeding diagnostic
monitor C209, and C208connections are noted, repair circuit 549. If necessary, add ground strap from circuit 549 (Black/Orange
wire) or 650 (Black/Light Blue wire) to one of the air bag diagnostic monitor mounting fasteners. Install
diagnostic monitor and go to next step. If no poor connections are noted, remove air bag diagnostic
monitor and bracket from vehicle and thoroughly clean mounting surfaces. Replace air bag diagnostic
monitor. Re-examine fault code and look for causes of high resistance in diagnostic monitor bracket
ground. Attempt to recreate hard faults by driving vehicle, flexing wiring harnesses, etc. Repair any
intermittent faults and go to next step.
8. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
Page 42
DTC B1922
-
SAFING SENSOR OUTPUT CIRCUIT SHORTED TO BATTERY VOLTAGE
wire). High voltage at specified terminals may also be caused by a short in air bag clockspring, or an internal air
1.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures voltage at terminal C209-2, circuit 614 (Gray/Orange wire), C209-3,
circuit 615 (Gray/White wire), C209-4, circuit 1113 (Yellow/Light Green wire), and C209-5, circuit 1112
(White/Light Blue wire) of air bag diagnostic monitor connector. Voltage at these terminals are set by
diagnostic monitor and vary with charging system voltage. If air bag diagnostic monitor measures more than 5
volts at any of these terminals, DTC B1922 will be stored in memory and AIR BAG warning light will flash
Code 22. If condition is repaired or intermittent, air bag diagnostic monitor will store DTC B1922 in memory.
VOLTAGE SPECIFICATIONS
Voltage At Terminal C209-2, C209-3, C209-4 or C209-5 System Voltage
1.5 9.0
1.6 9.5
1.7 10.0
1.8 10.5
1.9 11.0
2.0 11.5
2.1 12.0
2.2 12.5
2.3 13.0
2.4 13.5
2.5 14.0
2.6 14.5
2.7 15.0
2.8 15.5
2.9 16.0
Possible Causes
High voltage at air bag diagnostic monitor terminal C209-2, C209-3, C209-4, or C209-5 may be caused by a
short to battery or ignition on terminal C209-5, circuit 1112 (White/Light Blue wire), C209-2, circuit 614
(Gray/Orange wire), C209-3, circuit 615 (Gray/White wire), or C209-4, circuit 1113 (Yellow/Light Green
bag diagnostic monitor failure.
Test Procedure
Verify Condition
Page 43
Turn ignition switch to OFF position. Connect NGS tester to DLC. Ensure PAD switch is in ON position.
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor connector. Turn PAD switch
Blue/Orange wire) and ground. If voltage is greater than zero volts, go to next step. If voltage is not as
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Perform ON-DEMAND SELF-TEST . If DTC B1922 is retrieved, go to next step. If DTC B1922 is not
retrieved, go to step 3).
2. Check PAD Switch For Hard Fault
Turn PAD switch to OFF position. Perform ON-DEMAND SELF-TEST . If DTC B1922 was retrieved,
go to step 4). If DTC B1922 was not retrieved, replace PAD switch and go to step 14). See PAD
SWITCH under REMOVAL & INSTALLATION.
3. Check PAD Switch
Turn PAD switch to OFF position. Perform ON-DEMAND SELF-TEST . If DTC B1922 was retrieved,
replace PAD switch and go to step 14). See PAD SWITCH under REMOVAL & INSTALLATION. If
DTC B1922 was not retrieved, fault is intermittent and not present. Go to step 11).
4. Check Driver-Side Air Bag Module Circuit For Short
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Inspect driver-side air bag
wiring for potential short to speed control and/or horn wiring. Disconnect air bag diagnostic monitor.
Turn ignition switch to ON position. Measure voltage between terminals C209-2, circuit 614
(Gray/Orange wire) and C209-18, circuit 549 (Black/Orange wire). If voltage is greater than zero volts,
go to next step. If voltage is zero volts, go to step 6).
5. Check Circuit 614 For Short To Power
Turn ignition switch to OFF position. Carefully remove the connector locking wedge and shorting bar
diagnostic monitor connector C1, terminal No. 2. Remove driver-side Air Bag Simulator (105-00011).
Measure resistance between air bag diagnostic monitor C209-2, circuit 614 (Gray/Orange wire) and
C209-18, circuit 549 (Black/Orange wire). If voltage is greater than zero volts, repair circuit 614
(Gray/Orange wire). Reconnect and verify system. Go to step 14). If voltage is not as specified, repair
circuit 615 (Gray/White wire). Reconnect and verify system. Go to step 14).
6. Check Passenger-Side Air Bag Module Circuits For Short
to ON position. Measure voltage between diagnostic monitor harness connector terminal C209-5, circuit
1112 (White/Light Blue wire) and C209-18, circuit 549 (Black/Orange wire). If voltage is more than zero
volts, go to next step. If voltage is not as specified, replace air bag diagnostic monitor. See DISABLING
& ACTIVATING AIR BAG SYSTEM . Reconnect and verify system. Go to step 14).
7. Check Circuit 607 For Short To Power
Turn ignition switch to OFF position. Disconnect passenger-side Air Bag Simulator (105-00011) and
PAD switch connector C214. Measure voltage between PAD switch C214-1, circuit 607 (Light
Page 44
specified, go to step 10).
under REMOVAL
1, circuit 607 (Light Blue/Orange wire) and ground. If voltage is greater than zero volts, repair circuit 607
reactivate system and clear all DTCs. See
DISABLING & ACTIVATING AIR BAG SYSTEM
.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
8. Check Circuit 1112 And 1113 For Short To Power
Disconnect PAD switch connector C213. Measure voltage between PAD switch C213-3, circuit 1112
(Light Green/Purple wire) on harness side of connector and ground. If voltage is greater than zero volts,
go to next step. If voltage is not as specified, replace PAD switch. See PAD SWITCH
& INSTALLATION. Go to step 14).
9. Check Circuit 1112 For Short To Power
Remove shorting bar from PAD switch C213. Measure voltage between PAD switch C213-3, circuit
1112 (Light Green/Purple wire) on harness side of connector and ground. If voltage is greater than zero
volts, repair circuit 1112 (White/Light Blue wire) and go to step 14). If voltage is not as specified, repair
circuit 1113 (Yellow/Light Green wire) and go to step 14).
10. Check Circuit 607 For Short To Power
Remove shorting bar from harness side of Black connector. Measure voltage between PAD switch C214(Light Blue/Orange wire) and go to step 14). If voltage is not as specified, repair circuit 616 (Pink/Black
wire) and go to step 14).
11. Check For DTC Service
Deactivate system. See COMPLETE SYSTEM DEACTIVATION . Perform ON-DEMAND SELF-
TEST . If DTC B1922 was retrieved, go to next step. If DTC B1922 was not retrieved, go to step 14).
12. Check For Steering Column Shorts
Inspect driver-side air bag wiring harness for shorts to speed control or horn wiring. If problems are
noted, repair as necessary and go to step 14). If no problems are noted, go to next step.
13. Check For Intermittent Wire Shorts
Inspect circuit 614 (Gray/Orange wire) and 615 (Gray/White wire) to driver-side air bag module and
circuits 607 (Light Blue/Orange wire) and 616 (Pink/Black wire), 1112 (White/Light Blue wire), 1113
(Yellow/Light Green wire) for wire-to-wire shorts. If problems are noted, repair as necessary and go to
next step. If wiring is OK, re-examine fault code and look for causes of intermittent shorts to battery
voltage. Attempt to recreate hard faults by driving vehicle, flexing wiring harnesses, etc. Repair
intermittent problems and go to next step.
14. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
Page 45
DTC B1932
-
HIGH RESISTANCE OR OPEN IN DRIVER
-
SIDE AIR BAG CIRCUIT
wire) may be caused by a poor connection or corrosion where clockspring connects into main wiring harness, or
Go to step 9).
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
While the ignition is in ON position, air bag diagnostic monitor runs periodic checks on resistance of driverside and passenger-side air bag circuits. Normal resistance from terminal C209-2, circuit 614 (Gray/Orange
wire) (driver-side air bag feed) to terminal C209-3, circuit 615 (Gray/White wire) (driver-side air bag return) is
1.4-2.0 ohms. This resistance total results from the sum of components in the circuit. If resistance across these
two terminals exceeds 3.0 ohms, DTC B1932 will be stored in memory and AIR BAG warning light will flash
Code 32. If condition is repaired or corrected, DTC B1932 will be stored in memory.
Possible Causes
High resistance across terminal C209-2, circuit 614 (Gray/Orange wire) and C209-3, circuit 615 (Gray/White
an open circuit or high resistance in clockspring, driver-side air bag module or wiring harness in either circuit
614 (Gray/Orange wire) or 615 (Gray/White wire).
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1932 is retrieved, go to
next step. If DTC B1932 is not retrieved, go to step 6).
2. Check Air Bag Module Resistance
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Connect NGS tester to
DLC. Perform ON-DEMAND SELF-TEST . If DTC B1932 is retrieved, go to next step. If DTC B1932
is not retrieved, inspect clockspring wiring and connector that mates to driver-side air bag for damage.
Reactivate system. If DTC B1932 is retrieved, replace driver-side air bag module and go to step 9). See
DRIVER-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION.
3. Verify Condition
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Set multimeter to lowest
scale (200k/ohms or AUTO). Zero multimeter by touching leads together and record resistance reading.
Measure resistance between diagnostic monitor harness connector terminal C209-2, circuit 614
(Gray/Orange wire) and C209-3, circuit 615 (Gray/White wire). Subtract reading found when zeroing
multimeter. If resistance is greater than 3 ohms, go to next step. If resistance is less than 3 ohms, replace
air bag diagnostic monitor. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION.
Reconnect, verify, and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Page 46
DEMAND
side
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
4. Isolate Air Bag Module Resistance
Disconnect clockspring connector. Connect Air Bag Simulator (105-00011) to harness connector at base
of steering column. Zero multimeter by touching leads together and record reading. Measure resistance
between diagnostic monitor harness connector terminal C209-2, circuit 614 (Gray/Orange wire) and
C209-3, circuit 615 (Gray/White wire). Subtract reading found when zeroing multimeter. If resistance is
greater than 2.2 ohms, go to next step. If resistance is less than 2.2 ohms, replace clockspring. See
CLOCKSPRING under REMOVAL & INSTALLATION. Reconnect, verify, and reactivate system. Go
to step 9).
5. Check Circuit 614 For Open
Measure resistance between clockspring C233-1, circuit 614 (Gray/Orange wire) and air bag diagnostic
monitor C209-2, circuit 614 (Gray/Orange wire). If resistance is less than 3 ohms, repair circuit 615
(Gray/White wire). Reconnect, verify, and reactivate system. Go to step 9). If resistance is more than 3
ohms, repair circuit 614 (Gray/Orange wire) for open. Reconnect, verify, and reactivate system. See
DISABLING & ACTIVATING AIR BAG SYSTEM . Go to step 9).
6. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1932 was retrieved, go to next step. If DTC B1932 was not retrieved, go to step
9).
7. Check Air Bag Connections
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Set multimeter to lowest
scale (200K ohms or AUTO). Zero multimeter by touching leads together and record reading. Remove
plastic locking wedge from Gray harness side connector at base of steering column. Measure resistance
between diagnostic monitor harness connector terminals C209-2, circuit 614 (Gray/Orange wire) and
C209-3, circuit 615 (Gray/White wire) while wiggling wires at driver-side air bag module connector
where it mates to clockspring. Subtract reading found when zeroing multimeter. Visually inspect wiring
at driver-side air bag connector where it mates to clockspring for signs of corrosion in connectors and
poor crimps or bad connections. If resistance is less than 3 ohms or no wiring problems present, go to
next step. If resistance is greater than 3 ohms or other problems present, replace clockspring or driverair bag module if wiring problems or high resistance is found. Go to step 9).
8. Check Circuits 614 and 615
Inspect circuit 614 (Gray/Yellow wire) and 615 (Gray/White wire) for pinched or chafed wires leading to
high resistance. If problems are noted, repair as necessary and go to next step. If no problems are noted,
re-examine fault code and look for causes of intermittent high resistance or open in appropriate circuits.
Attempt to recreate hard faults by driving vehicle, flexing wiring harnesses, etc. Repair intermittent
problems and go to next step. If no problems are noted, go to next step.
9. Check For Other DTCs
Page 47
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
resistance is greater than 3 ohms, go to next step. If resistance is less than 3 ohms, replace air bag
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1933 - HIGH RESISTANCE OR OPEN IN PASSENGER-SIDE AIR BAG CIRCUIT
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
While the ignition is in ON position, air bag diagnostic monitor runs periodic checks on resistance of driverside and passenger-side air bag circuits. Normal resistance from terminal C209-5, circuit 1112 (White/Light
Blue wire) (passenger-side air bag feed) to terminal C209-4, circuit 1113 (Yellow/Light Green wire)
(passenger-side air bag return) is 0.9-1.2 ohms. This resistance total results from the sum of components in the
circuit. If resistance across these two terminals exceeds 3.0 ohms, DTC B1933 will be stored in memory and
AIR BAG warning light will flash Code 33. If condition is repaired or corrected, DTC B1933 will be stored in
memory.
Possible Causes
High resistance across terminal C209-5, circuit 1112 (White/Light Blue wire) and C209-4, circuit 1113
(Yellow/Light Green wire) may be caused by an open circuit or high resistance is wiring harness in either
terminal C209-5 or C209-4, passenger-side air bag module, or PAD switch.
Test Procedure
1. Verify Condition
Turn ignition switch to OFF position. Connect NGS tester to DLC. Change position of PAD switch.
Perform ON-DEMAND SELF-TEST . If DTC B1933 is retrieved, go to next step. If DTC B1933 is not
retrieved, go to step 5).
2. Check Air Bag Module Resistance
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Connect NGS tester to
DLC. Perform ON-DEMAND SELF-TEST . If DTC B1932 is retrieved, go to next step. If DTC B1933
is not retrieved, replace passenger-side air bag module and go to step 8). See PASSENGER-SIDE AIR
BAG MODULE under REMOVAL & INSTALLATION.
3. Verify Condition
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Remove plastic locking
wedge at diagnostic module connector. Zero multimeter by touching leads together and record resistance
reading. Measure resistance between diagnostic monitor C209-5, circuit 1112 (White/Light Blue wire)
and C209-4, circuit 1113 (Yellow/Light Green wire). Subtract reading found when zeroing multimeter. If
Page 48
diagnostic monitor. See
DIAGNOSTIC MONITOR
under REMOVAL & INSTALLATION.
1, circuit
Blue/Orange wire), 616 (Pink/Black wire), 1112 (Light Green/Purple wire), or 1113 (Yellow/Light Green
DEMAND
side air bag module if wiring
problems are noted, go to next step.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Reconnect, verify, and reactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM .
Go to step 8).
4. Check Circuits For Open
Disconnect passenger-side Air Bag Simulator (105-00011) and PAD switch connector. Remove
diagnostic module locking wedge. Measure resistance between PAD switch C213-3, circuit 1112 (Light
Green/Purple wire) and diagnostic monitor C209-5, circuit 1112 (White/Light Blue wire). Measure
resistance between PAD switch C213-1, circuit 1113 (Yellow/Light Green wire) and diagnostic monitor
C209-4, circuit 1113 (Yellow/Light Green wire). Measure resistance between PAD switch C214607 (Light Blue/Orange wire) and passenger-side air bag module C215-1, circuit 607 (Light Blue/Orange
wire). Measure resistance between PAD switch C214-3, circuit 616 (Pink/Black wire) and passenger-side
air bag module C215-3, circuit 616 (Pink/Black wire). If resistance readings are less than 3 ohms, replace
PAD switch. See DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect,
verify, and reactivate system. Go to step 8). If resistance is not as specified, repair circuit 607 (Light
wire). Reconnect, verify, and reactivate system. Go to step 8).
5. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1933 was retrieved, go to next step. If DTC B1933 was not retrieved, go to step
8).
6. Check Air Bag Connections
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Set multimeter to lowest
scale (200K ohms or AUTO). Zero multimeter by touching leads together and record reading. Remove
plastic locking wedge from Gray harness side connector at base of steering column. Measure resistance
between diagnostic monitor harness connector terminals C209-4, circuit 1112 (White/Light Blue wire)
and C209-5, circuit 1113 (Yellow/Light Green wire). Subtract reading found when zeroing multimeter.
Change position of PAD switch and perform resistance check again. Visually inspect wiring at passengerside air bag connector where it mates to clockspring for signs of corrosion in connectors and poor crimps
or bad connections. If resistance is less than 3 ohms or no wiring problems present, go to next step. If
resistance is more than 3 ohms or other problems present, replace passengerproblems or high resistance is found. Go to step 8).
7. Check Circuits 607, 616, 1112, & 1113
Inspect circuit 607 (Light Blue/Orange wire), 616 (Pink/Black wire), 1112 (White/Light Blue wire), and
1113 (Yellow/Light Green wire) for pinched or chafed wires leading to high resistance. If problems are
noted, repair as necessary and go to next step. If no problems are noted, re-examine fault code and look
for causes of intermittent high resistance or open in appropriate circuits. Attempt to recreate hard faults
by driving vehicle, flexing wiring harnesses, etc. Repair intermittent problems and go to next step. If no
Page 49
under REMOVAL &
side air bag
connector. Disconnect air bag diagnostic monitor. Remove plastic locking wedge from Gray harness
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
8. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1934 - LOW RESISTANCE OR SHORT IN DRIVER-SIDE AIR BAG CIRCUIT
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
While the ignition is in ON position, air bag diagnostic monitor runs periodic checks on resistance of driverside and passenger-side air bag circuits. Normal resistance from terminal C209-2, circuit 614 (Gray/Orange
wire) (driver-side air bag feed) to terminal C209-3, circuit 615 (Gray/White wire) (driver-side air bag return) is
1.4-2.0 ohms. This resistance total results from the sum of components in the circuit. If resistance across these
two terminals is less than 1.0 ohm, DTC B1934 will be stored in memory and AIR BAG warning light will
flash Code 34. If condition is repaired or corrected, DTC B1934 will be stored in memory.
Possible Causes
Low resistance across terminal C209-2, circuit 614 (Gray/Orange wire) and 615 (Gray/White wire) may be
caused by a poorly mated air bag connector, diagnostic monitor harness connector, or clockspring connector, a
damaged or worn shorten bar, a short in clockspring or wiring harness, or a short circuit or low resistance in
driver-side air bag module.
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1934 is retrieved, go to
next step. If DTC B1934 is not retrieved, go to step 5).
2. Check Air Bag Module Resistance
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Connect NGS tester to
DLC. Perform ON-DEMAND SELF-TEST . If DTC B1932 is retrieved, go to next step. If DTC B1934
is not retrieved, examine shorting bars on driver-side air bag module connector and inspect clockspring
wiring circuits 614 and 615 for damage or shorts. Replace driver-side air bag module if shorting bars are
normal and no wiring damage is found. See DRIVER-SIDE AIR BAG MODULE
INSTALLATION. Go to step 9).
3. Verify Condition
Turn ignition switch to OFF position. Disconnect Air Bag Simulator (105-00011) from driver-
Page 50
connector C209 at air bag diagnostic monitor. Measure resistance between diagnostic monitor harness
DEMAND
connector at main harness, and diagnostic monitor for signs of poor operation. If resistance is more than 1
main harness, and where clockspring mates to driver
-
side air bag module for potential intermittent shorts
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
connector terminal C209-2, circuit 614 (Gray/Orange wire) and C209-3, circuit 615 (Gray/White wire)
while turning steering wheel. If resistance reading is less than 10 Kohms, go to next step. If resistance is
not as specified, examine shorting bars on driver-side air bag module connector. Replace diagnostic
monitor if shorting bars are normal. See DIAGNOSTIC MONITOR under REMOVAL &
INSTALLATION. Reconnect and verify system. Go to step 9).
4. Check For Short Between Circuit 614 And 615
Disconnect clockspring connector at base of steering column. Measure resistance between diagnostic
monitor harness connector terminal C209-2, circuit 614 (Gray/Orange wire) and C209-3, circuit 615
(Gray/White wire). If resistance reading is greater than 10 Kohms, examine shorting bars on driver-side
air bag module connector. Replace clockspring if shorting bars are normal. See CLOCKSPRING under
REMOVAL & INSTALLATION. Reconnect system. Go to step 9). If resistance is not as specified,
repair short between circuit 614 (Gray/Orange wire) and 615 (Gray/White wire). Reconnect and verify
system. Go to step 9).
5. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1934 was retrieved, go to next step. If DTC B1934 was not retrieved, go to step
9).
6. Check Shorting Bars
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Zero multimeter by
touching leads together and record reading. Remove plastic locking wedge from Gray harness side
connector at base of steering column. Measure resistance between diagnostic monitor harness connector
terminals C209-2, circuit 614 (Gray/Orange wire) and C209-3, circuit 615 (Gray/White wire) while
wiggling wires at driver-side air bag module connector where it mates to clockspring. Subtract reading
found when zeroing multimeter. Visually inspect shorting bars at driver-side air bag module, clockspring
ohm or no wiring problems present, go to next step. If resistance is more than 1 ohm or other problems
present, repair as necessary. Go to step 9).
7. Check Clockspring
Remove Air Bag Simulator (105-00011) from steering wheel. Measure resistance between air bag
diagnostic monitor harness connector terminal C209-2, circuit 614 (Gray/Orange wire) and C209-3,
circuit 615 (Gray/White wire) while turning steering wheel. If resistance reading is not infinite (open), go
to next step. If resistance is infinite (open), replace clockspring if resistance reading jumps while turning
steering wheel. See CLOCKSPRING under REMOVAL & INSTALLATION. Go to step 9).
8. Check Circuits 614 and 615
Inspect circuit 614 (Gray/Yellow wire) and 615 (Gray/White wire), clockspring wires where it mates to
Page 51
between circuits. If problems are noted, repair as necessary and replace clockspring and driver
-
side air
Turn ignition switch to OFF position. Connect NGS tester to DLC. Ensure PAD switch is in ON position.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
bag if wiring is damaged. Go to next step. If no problems are noted, re-examine fault code and look for
causes of intermittent high resistance or open in appropriate circuits. Attempt to recreate hard faults by
driving vehicle, flexing wiring harnesses, etc. Repair intermittent problems and go to next step.
9. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1935 - LOW RESISTANCE OR SHORT IN PASSENGER-SIDE AIR BAG CIRCUIT
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor runs periodic checks on resistance of driver-side and passenger-side air bag
module, while ignition switch is in ON position. Normal resistance from terminal C209-5, circuit 1112
(White/Light Blue wire) (passenger-side air bag feed) to terminal C209-4, circuit 1113 (Yellow/Light Green
wire) (passenger-side air bag return) is between 0.9-1.2 ohms. If resistance at these terminals is less than 0.7
ohms, DTC B1935 will be stored in memory and AIR BAG warning light will flash Code 35. If condition is
repaired or corrected, DTC B1935 will be stored in memory.
Possible Causes
Low resistance across C209-5, circuit 1112 (White/Light Blue wire) and C209-4, circuit 1113 (Yellow/Light
Green wire) may be caused by a poorly mated passenger-side air bag or diagnostic monitor harness connector,
damaged or worn shorting bar, short in harness wires across specified circuits, or short or low resistance in
passenger-side air bag module or PAD switch.
Test Procedure
1. Verify Condition
Perform ON-DEMAND SELF-TEST . If DTC B1935 is retrieved, go to next step. If DTC B1935 is not
retrieved, go to step 8).
2. Check PAD Switch Position
Ensure PAD switch is in ON position. If PAD switch is in ON position, go to step 4). If PAD switch is in
OFF position, use key to turn PAD switch to ON position and go to next step.
3. Recheck System
Page 52
Perform
ON-DEMAND SELF
-
TEST
. If DTC B1935 was retrieved, go to next step. If DTC B1935 was
side air
is infinite (open), examine shorting bars on air bag diagnostic connector C209. Replace air bag diagnostic
(open), go to next step. If resistance is not as specified, repair circuit 1112 and/or 1113. Reconnect system
under REMOVAL & INSTALLATION. Reconnect system and
DEMAND
bag diagnostic monitor. Ensure PAD switch is in ON position. Zero multimeter by touching leads
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
not retrieved, replace PAD switch and go to step 12). See PAD SWITCH under REMOVAL &
INSTALLATION.
4. Check Air Bag Module Resistance
Deactivate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Connect NGS to DLC.
Perform ON-DEMAND SELF-TEST . If DTC B1935 is retrieved, go to next step. If DTC B1935 is not
retrieved, examine shorting bars on passenger-side air bag connector. Replace passenger-side air bag
module if shorting bars are normal. Go to step 7).
5. Verify Condition
Turn ignition switch to OFF position. Disconnect Air Bag Simulator (105-00011) from passengerbag connector. Disconnect air bag diagnostic monitor. Remove plastic locking wedge from Gray harness
connector C209 at air bag diagnostic monitor. Measure resistance between diagnostic monitor harness
connector terminal C209-4, circuit 1113 (Yellow/Light Green wire) and C209-5, circuit 1112
(White/Light Blue wire). If resistance reading is not infinite (open), go to next step. If resistance reading
monitor if shorting bars are normal. See DIAGNOSTIC MONITOR under REMOVAL &
INSTALLATION. Reconnect and verify system. Go to step 12).
6. Check For Short Between Circuit 1112 And 1113
Disconnect PAD switch connector C213. Measure resistance between PAD switch C213-1, circuit 1112
(White/Light Blue wire) and C213-3, circuit 1113 (Yellow/Light Green wire). If resistance is infinite
and inspect diagnostic monitor harness connector C209 for shorted terminals. Go to step 12).
7. Check For Short Between Circuit 607 And 616
Disconnect PAD switch connector C214. Measure resistance between PAD switch C214-1, circuit 607
(Light Blue/Orange wire) and C214-3, circuit 616 (Pink/Black wire). If resistance is infinite (open),
replace PAD switch. See PAD SWITCH
inspect diagnostic monitor harness connector C209 for shorted terminals. Go to step 12). If resistance is
not as specified, repair circuit 607 and/or 616. Reconnect, verify, and reactivate system. Go to step 12).
8. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1935 was retrieved, go to next step. If DTC B1935 was not retrieved, go to step
12).
9. Check Shorting Bars
Turn ignition switch to OFF position. Disconnect passenger-side Air Bag Simulator (105-00011) and air
Page 53
together and record reading. Remove plastic locking wedge from Gray harness side connector at base of
circuit 617. The air bag diagnostic monitor periodically pulls voltage at terminal C209
-
16, circuit 617
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
steering column. Measure resistance between diagnostic monitor C209-4, circuit 1113 (Yellow/Light
Green wire) and C209-5, circuit 1112 (White/Light Blue wire) while wiggling wires at passenger-side air
bag module connector where it mates to harness. Subtract reading found when zeroing multimeter.
Visually inspect shorting bars at passenger-side air bag and clockspring Gray harness connector for signs
of poor operation. If resistance is not infinite (open) or no wiring problems present, go to next step. If
resistance is infinite (open) or other problems present, repair as necessary and go to step 12).
10. Check PAD Switch Connections
Disconnect PAD switch connector C213. Zero multimeter by touching leads together and record reading.
Remove shorting bars from PAD switch connector C213. Measure resistance between PAD switch C2131, circuit 1112 (White/Light Blue wire) and C213-3, circuit 1113 (Yellow/Light Green wire), while
wiggling wires on PAD switch pigtail and turning PAD switch off and on. Subtract reading found when
zeroing multimeter. Inspect shorting bars on PAD switch pigtail connector C213, for signs of poor
operation. If any wiring problems are found or resistance reading is infinite (open), go to next step. If no
wiring problems are found and resistance reading is not infinite (open), replace PAD switch if wiring
problem is found or high resistance measured. See PAD SWITCH under REMOVAL &
INSTALLATION. Go to step 12).
11. Check Circuit 607, 616, 1112 And 1113
Inspect wiring and connections in circuits 607 (Light Blue/Orange wire), 616 (Pink/Black wire), 1112
(White/Light Blue wire), and 1113 (Yellow/Light Green wire) for potential intermittent shorts between
circuits. Examine harness connection air bag wires for same condition. If problems are noted, repair as
necessary and replace passenger-side air bag if wiring is damaged. Go to next step. If no problems are
noted, re-examine fault code and look for causes of intermittent high resistance or open in appropriate
circuits. Attempt to recreate hard faults by driving vehicle, flexing wiring harnesses, etc. Repair
intermittent problems and go to next step.
12. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1941 - RIGHT FRONT IMPACT SENSOR FEED/RETURN CIRCUIT OPEN
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
Voltage at terminal C209-16, circuit 617 (Pink/Orange wire) is set by air bag diagnostic monitor to be slightly
less than battery voltage. This circuit is connected to circuit 624 (Yellow/White wire) inside right front impact
sensor. Voltage at circuit 624 and diagnostic monitor C208-24 should be same as voltage at diagnostic monitor
Page 54
(Pink/Orange wire) low to verify connection to terminal C208
-
24, circuit 624 (Yellow/White wire). If voltage at
24. If any of voltage readings is greater than zero volts, repair appropriate circuit and go to step 10).
impact sensor. Measure resistance between right front impact sensor C140
-
2, circuit 617 (Pink/Orange
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
circuit 624 does not pull low as result of test, DTC B1941 will be stored in memory and AIR BAG warning
light will flash Code 41. If condition is repaired or corrected, DTC B1941 will be stored in memory.
Possible Causes
Failure to achieve low voltage at terminal C208-24, circuit 624 (Yellow/White wire) during test may be caused
by an open in wiring harness in either specified circuits, an open circuit inside right front impact sensor, or a
short to battery or ignition voltage in circuits 617 (Pink/Orange wire), 619 (Pink/White wire), 624
(Yellow/White wire), or 625 (Yellow/Light Green wire).
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1941 is retrieved, go to
next step. If DTC B1941 is not retrieved, go to step 6).
2. Measure Resistance
Turn ignition switch to OFF position. Deactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Disconnect air bag diagnostic monitor. Zero multimeter by touching leads together and
record resistance reading. Measure resistance between air bag diagnostic monitor harness connector
terminals C209-16, circuit 617 (Pink/Orange wire) and C208-24, circuit 624 (Yellow/White wire).
Subtract reading found when zeroing multimeter. If resistance is less than 5 ohms, go to next step. If
resistance is greater than 5 ohms, go to step 4).
3. Check For Short To Battery
Disconnect air bag diagnostic monitor connector. Turn ignition switch to ON position. Measure voltage
between air bag diagnostic monitor C209, C208, ground and terminals C209-15, C209-16, C208-23, and
C208If voltages are zero, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR under
REMOVAL & INSTALLATION. Reconnect and verify system. Go to step 10).
4. Verify Concern
Turn ignition switch to OFF position. Disconnect right front impact sensor connector. Measure resistance
between circuits 617 (Pink/Orange wire) and 624 (Yellow/White wire) on right front impact sensor. If
resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, replace right front
impact sensor. See FRONT IMPACT SENSORS under REMOVAL & INSTALLATION. Verify
system and go to step 10).
5. Check Circuit 617 For Open
Turn ignition switch to OFF position. Disconnect air bag diagnostic monitor. Disconnect right front
Page 55
wire) and air bag diagnostic monitor C209
-
16, circuit 617 (Pink/Orange wire). If resistance is less than 5
ohms, repair circuit 624 (Yellow/White wire) for an open. Reconnect, verify, and reactivate system. Go to
DEMAND
monitor circuit 619. The air bag diagnostic monitor periodically pulls voltage at terminal C209
-
15, circuit 619
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
step 10). If resistance is not as specified, repair circuit 617 (Pink/Orange wire). Reconnect, verify, and
reactivate system. Go to step 10).
6. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1941 was retrieved, go to next step. If DTC B1941 was not retrieved, go to step
10).
7. Check Wires
Inspect wires, crimps, connectors, etc. on circuits 617 (Pink/Orange wire) and 624 (Yellow/White wire)
for signs of poor connection. If problems are noted, repair and go to step 10). If not, go to next step.
8. Check For Short To Battery
Inspect circuits 617 (Pink/Orange wire), 619 (Pink/White wire), 624 (Yellow/White wire), and 625
(Yellow/Light Green wire) for signs of wire shorts, shorts to battery or ignition, or high voltage. If any
problems are noted, repair and go to step 10). If not, go to next step.
9. Check Sensor
Inspect right front impact sensor. Look for signs of corrosion. If problem or corrosion is noted, replace
right front impact sensor. See FRONT IMPACT SENSORS under REMOVAL & INSTALLATION.
Go to next step. If no problems are noted, re-examine fault code and look for causes of intermittent faults
or high resistance in applicable circuits. Attempt to recreate hard fault codes by driving vehicle, flexing
wiring harness, cycling ignition switch, etc. Service intermittent problems. Go to next step.
10. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1942 - LEFT FRONT IMPACT SENSOR FEED/RETURN CIRCUIT OPEN
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
Voltage at terminal C209-15, circuit 619 (Pink/White wire) is set by air bag diagnostic monitor to be slightly
less than battery voltage. This circuit is connected to circuit 625 (Yellow/Light Green wire) inside left front
impact sensor. Voltage at circuit 625 and diagnostic monitor C208-23 should be same as voltage at diagnostic
Page 56
(Pink/White wire) low to verify connection to terminal C208
-
23, circuit 625 (Yellow/Light Green wire). If
24. If any of voltage readings is greater than zero volts, repair appropriate circuit and go to step 10).
15, circuit 619 (Pink/White wire). If resistance is less than 5 ohms, repair circuit
625 (Yellow/Light Green wire) for an open. Reconnect, verify, and reactivate system. Go to step 10). If
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
voltage at circuit 625 does not pull low as result of test, DTC B1942 will be stored in memory and AIR BAG
warning light will flash Code 42. If condition is repaired or corrected, DTC B1942 will be stored in memory.
Possible Causes
Failure to achieve low voltage at terminal C208-23, circuit 625 (Yellow/Light Green wire) during test may be
caused by an open in wiring harness in either specified circuits, an open circuit inside left front impact sensor,
or a short to battery or ignition voltage in circuits 617 (Pink/Orange wire), 619 (Pink/White wire), 624
(Yellow/White wire), or 625 (Yellow/Light Green wire).
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1942 is retrieved, go to
next step. If DTC B1941 is not retrieved, go to step 6).
2. Measure Resistance
Turn ignition switch to OFF position. Deactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Disconnect air bag diagnostic monitor. Zero multimeter by touching leads together and
record resistance reading. Measure resistance between air bag diagnostic monitor harness connector
terminals C209-15, circuit 619 (Pink/White wire) and C208-23, circuit 625 (Yellow/Light Green wire).
Subtract reading found when zeroing multimeter. If resistance is less than 5 ohms, to next step. If
resistance is greater than 5 ohms, go to step 4).
3. Check For Short To Battery
Disconnect air bag diagnostic monitor connector. Turn ignition switch to ON position. Measure voltage
between air bag diagnostic monitor C209, C208, ground and terminals C209-15, C209-16, C208-23, and
C208If voltages are zero, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR under
REMOVAL & INSTALLATION. Reconnect and verify system. Go to step 10).
4. Verify Concern
Disconnect left front impact sensor connector. Measure resistance between left front impact sensor
terminals No. 1 and 2. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5
ohms, replace left front impact sensor. See FRONT IMPACT SENSORS under REMOVAL &
INSTALLATION. Verify system and go to step 10).
5. Check Circuit 619 For Open
Measure resistance between left front impact sensor C141-2, circuit 619 (Pink/White wire) and air bag
diagnostic monitor C209-
Page 57
resistance is not as specified, repair circuit 619 (Pink/White wire). Reconnect, verify, and reactivate
DEMAND
wire) for signs of poor connection. If problems are noted, repair and go to step 10). If not, go to next step.
will be stored in memory.
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
system. Go to step 10).
6. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1942 was retrieved, go to next step. If DTC B1942 was not retrieved, go to step
10).
7. Check Wires
Inspect wires, crimps, connectors, etc. on circuits 619 (Pink/White wire) and 625 (Yellow/Light Green
8. Check For Short To Battery
Inspect circuits 617 (Pink/Orange wire), 619 (Pink/White wire), 624 (Yellow/White wire), and 625
(Yellow/Light Green wire) for signs of wire shorts, shorts to battery or ignition, or high voltage. If any
problems are noted, repair and go to step 10). If not, go to next step.
9. Check Sensor
Inspect left front impact sensor. Look for signs of corrosion. If problem or corrosion is noted, replace left
front impact sensor. See FRONT IMPACT SENSORS under REMOVAL & INSTALLATION. Go to
next step. If no problems are noted, re-examine fault code and look for causes of intermittent faults or
high resistance in applicable circuits. Attempt to recreate hard fault codes by driving vehicle, flexing
wiring harness, cycling ignition switch, etc. Service intermittent problems. Go to next step.
10. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1944 - RIGHT FRONT IMPACT SENSOR NOT MOUNTED TO VEHICLE
PROPERLY/GROUND CIRCUIT OPEN
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures resistance between C208-21, circuit 618 (Purple/Light Green wire)
and reference ground at terminal C209-18, circuit 549 (Black/Orange wire). If diagnostic monitor measures
difference of more than 3 ohms between ground at C209-18 and ground at C208-21, DTC B1944 will be stored
in memory and AIR BAG warning light will flash Code 44. If condition is repaired or corrected, DTC B1944
Page 58
Possible Causes
6.
Check For DTC Service
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
High resistance at terminal C208-21, circuit 618 (Purple/Light Green wire) to ground may be caused by a poor
attachment of right front impact sensor due to loose mounting, dirt or corrosion, an open or damaged wire in
circuit 618, an open wire or loose rivet inside right front impact sensor, or a poor reference ground at applicable
circuits.
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1944 is retrieved, go to
next step. If DTC B1944 is not retrieved, go to step 6).
2. Check Circuit 618
Turn ignition switch to OFF position. Deactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Disconnect air bag diagnostic monitor. Measure resistance between terminal C208-21, circuit
618 (Purple/Light Green wire) and ground. If resistance is greater than 3 ohms, go to next step. If
resistance is less than 3 ohms, go to step 5).
3. Check Front Impact Sensor Ground
Disconnect right front impact sensor connector. Zero multimeter by touching leads together and record
reading. Measure resistance between right front impact sensor terminal No. 4 and ground. Subtract
reading found when zeroing multimeter. If resistance is greater than 3 ohms, remove screws retaining
sensor, clean mounting surface, and install sensor. Go to next step. If resistance is not as specified, repair
circuit 618 (Purple/Light Green wire). Reconnect system and go to step 10).
4. Check Right Front Impact Sensor
Zero multimeter by touching leads together and record reading. Measure resistance between right front
impact sensor terminal No. 4 and ground. If resistance is less than 3 ohms, reconnect system and go to
step 10). If resistance is greater than 3 ohms, replace right impact sensor. See FRONT IMPACT
SENSORS under REMOVAL & INSTALLATION. Reconnect system. Go to step 10).
5. Check Reference Ground
Check attachment of ground connections and splices in feeding air bag diagnostic monitor C209-18,
circuit 549 (Black/Orange wire) and C208-10, circuit 650 (Black/Light Blue wire). If any poor
connections are noted, check poor grounding of circuit 549 and 650. If necessary, add ground strap from
circuit 549 to one of diagnostic monitor mounting fasteners. Connect air bag diagnostic monitor and
verify system. Go to step 10). If no poor connections are noted, replace air bag diagnostic monitor. See
DIAGNOSTIC MONITOR under REMOVAL & INSTALLATION. Reconnect and verify system. Go
to step 10).
Page 59
DEMAND
in memory and AIR BAG warning light will flash Code 45. If condition is repaired or corrected, DTC B1945
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ONSELF-TEST . If DTC B1944 was retrieved, go to next step. If DTC B1944 was not retrieved, go to step
10).
7. Check Wires
Inspect wires, crimps, connectors, etc. on circuits 618 (Purple/Light Green wire) and 649 (Black/Orange
wire) for signs of poor connection. Connect NGS to DLC. Select IABM. Select Pid/Data Monitor and
Record. Select Pid CRSHSN1. Wiggle wires while watching PID. If reading goes greater than 3 ohms or
other problems are noted, repair and go to step 10). If not, go to next step.
8. Check Sensor
Inspect right front impact sensor for signs of corrosion. Connect NGS to DLC. Select IABM. Select
Pid/Data Monitor and Record. Select Pid CRSHSN1. Wiggle wires while watching PID. If reading goes
greater than 3 ohms or other problems are noted, replace front impact sensor and repair problems. Go to
step 10). If not, go to next step.
9. Check Circuit 549 And 650
Check attachment of ground connections feeding air bag diagnostic monitor C209-18, circuit 549
(Black/Orange wire) and C208-10, circuit 650 (Black/Light Blue wire). If any poor ground connections
are found, check poor grounding of circuits 549 and 650. If necessary, add ground strap from circuit 549
to one of air bag diagnostic monitor mounting fasteners. Connect air bag diagnostic monitor and verify
system. Go to next step. If no poor ground connections are found, remove front impact sensor retaining
screws and clean mounting surface of sensor and chassis. Install sensor and tighten screws. Go to next
step.
10. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
DTC B1945 - LEFT FRONT IMPACT SENSOR NOT MOUNTED TO VEHICLE
PROPERLY/GROUND CIRCUIT OPEN
NOTE: Before proceeding, see SERVICE PRECAUTIONS . After servicing has been
performed, recheck AIR BAG warning light. If system is okay, install air bag
modules and reactivate air bag system.
Description
The air bag diagnostic monitor measures resistance between C208-20, circuit 620 (Purple/Light Blue wire) and
reference ground at terminal C209-18, circuit 549 (Black/Orange wire). If diagnostic monitor measures
difference of more than 3 ohms between ground at C209-18 and ground at C208-20, DTC B1945 will be stored
Page 60
will be stored in memory.
reading found when zeroing multimeter. If resistance is less than 3 ohms, repair circuit 620 and reconnect
18. If any poor connections are noted,
REMOVAL & INSTALLATION. Reconnect and verify system. Go to step 10).
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Possible Causes
High resistance at terminal C208-20, circuit 620 (Purple/Light Blue wire) to ground may be caused by a poor
attachment of left front impact sensor due to loose mounting, dirt or corrosion, an open or damaged wire in
circuit 620, an open wire or loose rivet inside left front impact sensor, or a poor reference ground at applicable
circuits.
Test Procedure
1. Verify Condition
Connect NGS tester to DLC. Perform ON-DEMAND SELF-TEST . If DTC B1945 is retrieved, go to
next step. If DTC B1945 is not retrieved, go to step 6).
2. Measure Resistance
Turn ignition switch to OFF position. Deactivate SRS. See DISABLING & ACTIVATING AIR BAG
SYSTEM . Disconnect air bag diagnostic monitor. Measure resistance of terminal C209-20, circuit 620
(Purple/Light Blue wire) to ground. If resistance is greater than 3 ohms, go to next step. If resistance is
less than 3 ohms, go to step 5).
3. Check Front Impact Sensor Ground
Disconnect left front impact sensor connector C141. Zero multimeter by touching leads together and
record reading. Measure resistance between left front impact sensor terminal No. 4 and ground. Subtract
system. Go to step 10). If resistance is not as specified, remove left front impact sensor retaining screws
and clean mounting surface of sensor and chassis. Install sensor and tighten screws. Go to step 10).
4. Check Left Front Impact Sensor
Zero multimeter by touching leads together and record reading. Measure resistance between left front
impact sensor terminal No. 4 and ground. If resistance is less than 3 ohms, reconnect system and go to
step 10). If resistance is greater than 3 ohms, replace left impact sensor. See FRONT IMPACT
SENSORS under REMOVAL & INSTALLATION. Reconnect system. Go to step 10).
5. Check Reference Ground
Check attachment of ground connections and splices in circuit 549 (Black/Orange wire) feeding air bag
diagnostic monitor harness connector terminals C208-10 and C209correct problem and if necessary add a ground strap from circuit 549 (Black/Orange wire) to one of the
diagnostic monitor mounting fasteners. Connect air bag diagnostic monitor. Verify system and go to step
10). If connections are OK, replace air bag diagnostic monitor. See DIAGNOSTIC MONITOR under
Page 61
DEMAND
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
6. Check For DTC Service
Deactivate system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Perform ON-
SELF-TEST . If DTC B1945 was retrieved, go to next step. If DTC B1945 was not retrieved, go to step
10).
7. Check Wires
Inspect wires, crimps, connectors, etc. on circuits 620 (Purple/Light Blue wire) for signs of poor
connection. Connect NGS to DLC. Select IABM. Select Pid/Data Monitor and Record. Select Pid
CRSHSN1. Wiggle wires while watching PID. If reading goes greater than 3 ohms or other problems are
noted, repair and go to step 10). If not, go to next step.
8. Check Sensor
Inspect left front impact sensor for signs of corrosion. Connect NGS to DLC. Select IABM. Select
Pid/Data Monitor and Record. Select Pid CRSHSN1. Wiggle wires while watching PID. If reading goes
greater than 3 ohms or other problems are noted, repair and go to step 10). If not, go to next step.
9. Check Circuit 549 And 650
Check attachment of ground connections feeding air bag diagnostic monitor C209-18, circuit 549
(Black/Orange wire) and C208-10, circuit 650 (Black/Light Blue wire). If any poor ground connections
are found, check poor grounding of circuits 549 and 650. If necessary, add ground strap from circuit 549
to one of air bag diagnostic monitor mounting fasteners. Connect air bag diagnostic monitor and verify
system. Go to next step. If no poor ground connections are found, remove front impact sensor retaining
screws and clean mounting surface of sensor and chassis. Install sensor and tighten screws. Go to next
step.
10. Check For Other DTCs
Connect NGS to DLC. If other DTCs are retrieved go to proper DTC test. If no other DTCs are retrieved,
reactivate system and clear all DTCs. See DISABLING & ACTIVATING AIR BAG SYSTEM .
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
Application Ft. Lbs. (N.m)
Steering Wheel Bolt 23-32 (31-44)
INCH Lbs. (N.m)
Driver-Side Air Bag Module 90-123 (10-13)
Front Sensors 10-123 (10-13)
PAD Switch 17-26 (2-3)
Passenger-Side Air Bag Module 87-92 (8-10)
Page 62
WIRING DIAGRAM
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Page 63
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Page 64
Fig. 11: SRS Wiring Diagram
1997 Ford Pickup F150
AIR BAG RESTRAINT SYSTEM (F150 & F250 LD) 1997 ACCESSORIES/SAFETY EQUIPMENT Ford Motor Co. - Air
Bag Restraint System
Page 65
ANTI
-
LOCK BRAKE SYSTEM
- 4-
WHEEL
(EHCU), master cylinder, power brake booster, front wheel speed sensors, rear wheel speed sensor (mounted on
1997 Ford Pickup F150
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
DESCRIPTION
CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in the GENERAL
INFORMATION section.
The 4-wheel Anti-Lock Brake System (ABS) is designed to allow vehicle to stop in the shortest possible
distance while maintaining full steering control. ABS system consists of Electronic Hydraulic Control Unit
differential). ABS uses electronic and hydraulic components to prevent wheels from locking up during brake
application. ABS does not function during normal (light) braking applications.
The EHCU consists of an Electronic Control Module (ECM) attached to a Hydraulic Control Unit (HCU). If
service is required, ECM can be replaced if inoperative. If HCU is inoperative, entire EHCU must be replaced
as an assembly.
NOTE: For more information on brake system, see BRAKE SYSTEM article in the
BRAKES section.
OPERATION
ABS control module receives a signal from each speed sensor. This information is translated into calculated
wheel speed. When ABS control module determines wheel lock-up is about to occur, the hydraulic control unit
is activated and deactivated to vary hydraulic pressure to prevent wheel lock-up.
ABS does not operate during normal braking conditions. ABS is self-monitoring. ABS has a self-diagnostic
system to obtain trouble codes for testing purposes. See DIAGNOSIS & TESTING .
BLEEDING BRAKE SYSTEM
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is
spilled onto a painted or plastic surface, immediately wash it with water.
Bleed hydraulic system whenever air has been introduced into system. Bleed master cylinder and brakes at all 4
wheels if master cylinder lines have been disconnected or master cylinder has run dry. Bleed brakes with
pressure bleeding equipment or by manually pumping brake pedal while using bleeder tubes. Always bleed
brakelines in sequence. See BLEEDING SEQUENCE .
CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in the GENERAL
INFORMATION section.
Page 66
fluid. Install plugs in front and rear brake outlet ports. Bleed front brake system first. Loosen plug in front
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
CAUTION: Bleed anti-lock brake system using following procedure. If this procedure
is not followed, air will be trapped in Hydraulic Control Unit (HCU),
resulting in a spongy pedal.
NOTE: DO NOT allow reservoir to run dry during bleeding operation.
MASTER CYLINDER BLEEDING (BENCH)
1. Support brake master cylinder body in a vise and fill brake master cylinder reservoir with DOT 3 brake
brake outlet port and depress primary piston slowly to force air out of master cylinder.
2. Tighten plug while piston is depressed or air will enter brake master cylinder. Repeat procedure until no
air bubbles are present. Repeat bleeding procedure for rear brake outlet port with front brake outlet
plugged. Tighten plugs and try to depress piston. Piston will not depress if all air is out of master
cylinder.
MASTER CYLINDER BLEEDING (ON VEHICLE)
1. Using a tubing wrench, remove brake tubes from master cylinder. Install short brake tubes in master
cylinder and position them so they curve into master cylinder reservoir. Ensure ends of tubes are
submerged in brake fluid.
2. Fill master cylinder reservoir with new DOT 3 brake fluid. Have an assistant pump brakes until clear,
bubble-free fluid flows from both brake tubes. Remove short brake tubes and reinstall brake tubes on
master cylinder. Bleed each brake tube at master cylinder by having and assistant pump brake pedal 10
times and hold firm pressure on brake pedal.
3. Loosen rear-most brake tube fittings until a stream of brake fluid comes out. Have an assistant maintain
pressure on brake pedal until brake tube fitting is tightened again. Repeat procedure until clear, bubblefree fluid comes out from around tube fitting. Refill master cylinder reservoir as necessary. Repeat this
bleeding operation at front brake tube fittings.
CONVENTIONAL MANUAL BLEEDING
1. Remove dust cap from right rear wheel bleeder fitting. Connect hose to bleeder fitting. Submerge other
end of hose in container of clean brake fluid.
2. Loosen bleeder fitting while an assistant presses brake pedal through its full travel. Close bleeder fitting.
Wait 5 seconds. Repeat procedure until air bubbles are no longer present at submerged end of hose.
3. Repeat procedure at left rear, right front and left front wheels. Refill reservoir after each wheel is bled.
When complete, adjust fluid level.
CONVENTIONAL PRESSURE BLEEDING
1. Clean reservoir cap area. Connect pressure bleeder, following manufacturer's instructions. Remove dust
cap from right rear wheel bleeder fitting. Attach hose to bleeder fitting. Submerge other end of hose in
container of clean brake fluid.
Page 67
With brake pedal released, open bleeder fitting until air bubbles no longer emerge from submerged end of
Bleed brake system using conventional bleeding procedure. Connect New Generation Star (NGS) tester to
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
CAUTION:
2. Open valve on bleeder tank to pressurize system. Maintain system pressure at 10-30 psi (.7-2.1 kg/cm2 ).
hose.
3. Repeat procedure at left rear, right front and left front wheels. When complete, close pressure bleeder
tank valve, remove adapter and adjust fluid level.
HYDRAULIC CONTROL UNIT (HCU) BLEEDING
1.
Data Link Connector (DLC). Turn ignition on. Enter vehicle identification information. Choose
DIAGNOSTIC DATA LINK from menu selection.
2. Next, choose ABS MODULE, FUNCTION TEST, and SERVICE BLEED FUNCTION. Follow scan
tester instructions until SERVICE BLEED PROCEDURE COMPLETE message is displayed. Repeat
conventional bleeding procedure again. If brake pedal feels spongy, repeat complete procedure.
Never exceed 50 psi (3.5 kg/cm2 ) during bleeding.
BLEEDING SEQUENCE
BLEEDING SEQUENCE
Application Sequence
Expedition & F150/250 Pickup RR, LR, RF, LF
TROUBLE SHOOTING
ANTI-LOCK WARNING LIGHT
The ABS and BRAKE warning lights alert vehicle operator of problems in braking system. Red BRAKE
warning light monitors master cylinder fluid level and parking brake status. Yellow ABS warning light alerts
vehicle operator to problems in ABS system.
DIAGNOSIS
CAUTION: When battery is disconnected, vehicle computer and memory systems
may lose memory data. Driveability problems may exist until computer
systems have completed a relearn cycle. See COMPUTER RELEARN
PROCEDURES article in the GENERAL INFORMATION section before
disconnecting battery. Vehicle may need to be driven more than 10 miles
to relearn strategy.
RETRIEVING TROUBLE CODES
NOTE: It is imperative that SYSTEM PRECHECK be performed before attempting any
Page 68
DTCs do not clear, check for additional stored DTCs.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
further diagnosis. Failure to do so could result in improper diagnosis.
1. Turn ignition off. Locate Data Link Connector (DLC) under dash, to right of steering column. Following
manufacturer's instructions, connect New Generation Star (NGS) Tester (007-00500) to DLC.
2. Turn ignition on. Follow instructions on scan tester menu. Record codes in order received. These codes
indicate current faults in system and should be serviced in order of appearance. See DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table.
DIAGNOSTIC TROUBLE CODE (DTC) INDEX
DTC Definition Proceed To
C1220 Yellow ABS Warning Indicator Failure TEST A
C1225/C1226 Red BRAKE Warning Indicator Failure TEST B
C1265 Shorted Red BRAKE Indicator Relay TEST B
C1198/C1200 Left Front Isolation Valve TEST C
C1194/C1196 Left Front Dump Valve TEST C
C1214/C1216 Right Front Isolation Valve TEST C
C1210/C1212 Right Front Dump Valve TEST C
C1206/C1208 Rear Isolation Valve TEST C
C1202/C1204 Rear Dump Valve TEST C
C1155 Left Front Wheel Speed Sensor, Static TEST D
C1158/C1233 Left Front Wheel Speed Sensor, Dynamic TEST E
C1145 Right Front Wheel Speed Sensor, Static TEST F
C1148/C1234 Right Front Wheel Speed Sensor, Dynamic TEST G
C1230 Rear Wheel Speed Sensor, Static TEST H
C1229/C1237 Rear Wheel Speed Sensor, Dynamic TEST J
No Code Soft/Excessive Pedal Travel (EHCU) TEST K
C1095/C1096 Pump Motor TEST L
C1113/C1115 Internal Power Relay TEST M
C1185 Open Internal Power Relay TEST M
No Code No Module Commuications TEST N
C1184 ABS System Timeout TEST P
C1222 Wheel Speed Error, Dynamic TEST P
C1169 Excessive Dump Time TEST R
B1342 ECU Failure
(1)
(1)
Temporarily substitute a known-good EHCU.
CLEARING TROUBLE CODES
DTCs can be cleared using the NGS tester. After 80 ignition cycles, provided vehicle has reached at least 15
MPH between each cycle, the control module clears DTCs automatically. Stored DTCs should be cleared. If
Page 69
SYSTEM PRECHECK
are intact and fully seated. Inspect system ground located at left front radiator support is clean and tight. If
to next step. If fuse is not okay, replace fuse and/or repair short to ground in Orange/Yellow wire between
. If warning indicator does not come on,
.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
NOTE: It is imperative that this procedure be performed before attempting any further
diagnosis. Failure to do so could result in improper diagnosis.
1. Verify all electrical connectors are connected to EHCU and wheel speed sensors are secure and free of
contamination or corrosion. Ensure fuse No. 14 (60-amp) located in engine compartment fuse panel is
intact and fully seated. Ensure fuses No. 13 (15-amp) and No. 25 (5-amp) located in interior fuse panel
all connections are secure and fuses are fully seated, go to next step. If all connections are not secure
and/or fuses are not fully seated, correct condition and go to next step.
2. Ensure ignition is off. Ensure parking brake is released. Turn ignition on. If both Red and Yellow
warning indicators come on and go off, go to next step. If one or both warning indicators stay on, go to
next step. If Yellow warning indicator never comes on, go to step 6 . If Red warning indicator never
comes on, go to step 8 . If both warning indicators never come on, replace fuse No. 25.
3. Turn ignition off. Connect New Generation Star (NGS) tester, following manufacturer's instructions.
Retrieve and record all DTC's. If DTC's are retrieved, go to DIAGNOSTIC TROUBLE CODE (DTC)
INDEX table under DIAGNOSIS. If system pass is obtained and concern is still present, go to
SYMPTOM DIAGNOSIS . If system pass is obtained and no further information is available, go to
DRIVE CYCLE TEST . If no response is obtained, go to next step.
4. Remove and inspect fuse No. 14 (60-amp) located in engine compartment fuse panel. If fuse is okay, go
fuse panel and ECU.
5. Ensure ignition is off. Disconnect negative battery cable. Measure resistance between negative battery
cable connector (battery end) and EHCU ground eyelet located at left front radiator support. If resistance
is less than one ohm, go to TEST N: NO MODULE COMMUNICATIONS . If resistance is more than
one ohm, repair ground circuit as necessary. See WIRING DIAGRAMS .
6. Connect 60-pin breakout box to EHCU with ABS adapter cable. Reconnect negative battery cable.
Connect fused jumper wire between ground and breakout box test terminal No. 1. Turn ignition on and
observe Yellow ABS warning indicator. If warning indicator comes on, temporarily substitute a knowngood EHCU and retest. If warning indicator does not come on, go to next step.
7. With ignition still on, measure voltage between ground and breakout box test terminal No. 1. If voltage is
less than 10 volts, repair Dark Green or Red/Yellow wire between EHCU and fuse No. 29. See WIRING
DIAGRAMS . If voltage is more than 10 volts, repeat step 6 .
8. Engage parking brake and observe Red BRAKE warning indicator. If warning indicator comes on, go to
TEST B: RED BRAKE WARNING INDICATOR FAILURE
go to next step.
9. Remove and inspect Red BRAKE warning indicator bulb. If bulb is blown, replace bulb and go to step 2
If bulb is okay, repair open in Red/Yellow wire between bulb and fuse No. 29. See WIRING
DIAGRAMS .
DRIVE CYCLE TEST
NOTE: Use drive cycle test to verify a repair, recreate an intermittent problem or
Page 70
clear all DTCs. Turn ignition off. Start engine and place transmission selector in 1 position. Allow vehicle
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
attempt to detect symptom when DTC or concern is unknown.
NOTE: Wetting down area where stop is to be performed will aid in performing this
test. Have an assistant monitor wheels during ABS stop. Momentary lockup is
permissible.
1. Drive vehicle at about 10 MPH. Press brake pedal hard enough to lock all 4 wheels. If one wheel locks
consistently and Yellow ABS warning indicator does not come on, go to SYMPTOM DIAGNOSIS . If
one wheel locks consistently and Yellow ABS warning indicator comes on and stays on, go to step 7 . If
one wheel does not lock consistently and Yellow ABS warning indicator does not come on, go to next
step.
2. Drive vehicle at about 20 MPH. Perform light to medium (normal traffic) stop. If pump motor turns on
and pedal pulsations are felt and Yellow ABS warning indicator does not come on, go to ABS MISFIRE,
ABS TOO SENSITIVE, ABS FIRES ON NORMAL STOP under SYMPTOM DIAGNOSIS . If pump
motor turns on and pedal pulsations are felt and Yellow ABS warning indicator comes on and stays on,
go to step 7 . If pump motor does not turn on and pedal pulsations are not felt and no other symptoms are
detected, go to step 6 . If pump motor does not turn on and pedal pulsations are not felt and Yellow ABS
warning indicator does not come on, go to next step.
3. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
to creep forward at idle for at least 45 seconds. If Yellow ABS warning indicator comes on, go to step 8 .
If warning indicator does not come on, turn ignition off and go to next step.
4. Using NGS tester, clear all DTCs. Turn ignition off. Start vehicle and accelerate to 25 MPH. Let at least
45 seconds elapse before reaching 25 MPH. If Yellow ABS warning indicator comes on, go to step 8 . If
warning indicator does not come on, go to next step.
5. If concern has been addressed and corrected by previous actions, ABS function has been verified. If
concern has been addressed and corrected by previous actions, go to SYMPTOM DIAGNOSIS .
6. Check for the following conditions: Lack of sufficient vehicle deceleration upon brake application.
Vehicle pulling during braking and pump motor does not come on. If any of these symptoms are present,
go to SYMPTOM DIAGNOSIS . If these symptoms are not present, concern is not in ABS system.
Check base brake system.
7. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
retrieve and record all DTCs. If DTC is the same as before and the test for the DTC is completed, go to
INTERMITTENT FAILURES . If DTC is not the same as before and the test for the DTC is not
completed, return to last completed step in test. If DTC is not the same, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If EHCU does not
respond, go to SYSTEM PRECHECK .
8. Using NGS tester, retrieve and record all DTCs. If sensor code is present, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES for appropriate test.
If sensor code is not present, and system pass was not obtained, go to DIAGNOSTIC TROUBLE
CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES and perform indicated test. If no
code or system pass was obtained, go to SYSTEM PRECHECK .
SYMPTOM DIAGNOSIS
Page 71
Rear brake adjustment, linings, wheel cylinders, parking brake rear axle seal. Eliminate base brake system
Brake line or hose, master cylinder, wheel cylinder, caliper, air in system, power brake booster. Eliminate
Brake line or hose, master cylinder, wheel cylinder, caliper, air in system, power brake booster. Eliminate
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
NOTE: It is imperative that SYSTEM PRECHECK be performed before attempting any
further diagnosis. Failure to do so could result in improper diagnosis.
ABS Misfire, ABS Too Sensitive, ABS Fires On Normal Stop
Possible source of problem may be:
Damaged rear sensor ring. Remove rear sensor from differential and inspect sensor ring.
Damaged front sensor ring. Inspect both front sensor rings for damaged or missing teeth.
Sensor output out of sync. If left front sensor output is out of sync, go to TEST E . If right front sensor
output is out of sync, go to TEST G . If rear sensor output is out of sync, go to TEST J .
Sensor circuit. Go to INTERMITTENT FAILURES to test sensor circuits.
Wire insulation. Inspect wiring harness from front sensor knuckle to frame for worn of chafed wire
insulation.
Rear brake adjustment, brake linings. Eliminate base brake system as cause of problem.
Loose sensors. Tighten sensors.
Wheels Lock Up
Possible source of problem may be:
Hydraulic outlet (dump) valve. Go to TEST K .
Leaky inlet (isolation) valve. Go to TEST K .
as cause of problem.
Hard Or Soft Brake Pedal
Possible source of problem may be:
Hydraulic inlet valve (hard pedal) or outlet valve (soft pedal). Go to TEST K .
base brake system as cause of problem.
Lack Of Deceleration During Medium/Hard Brake Application
Possible source of problem may be:
Shut inlet (isolation) valve, outlet (dump) valve (rear axle only). Go to TEST K .
base brake system as cause of problem.
Vehicle Pulls During Braking
Page 72
Possible source of problem may be:
Rear brake adjustment, faulty caliper, brake pads or shoes, brakeline or hose. Eliminate base brake system
. If voltage is more than zero volt at any time, repair short to voltage in Dark
test and retrieve DTCs. If DTC C1220 is retrieved
1.
Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
as cause of problem.
Front inlet (isolation) valve. Temporarily substitute a known-good EHCU and retest.
Yellow ABS Warning Indicator On With System Pass
Possible source of problem may be:
Electrical circuit. Disconnect 24-pin connector from EHCU. If indicator is on, repair short to ground in
Dark Green wire between EHCU and indicator. If indicator is off, temporarily substitute a known-good
EHCU and retest.
TEST A: YELLOW ABS WARNING INDICATOR FAILURE
NOTE: This test is associated with DTC C1220.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Turn ignition off then on. Observe Yellow ABS warning indicator prove out. If warning
indicator proves out properly, problem is intermittent; go to step 4 . If warning indicator does not prove
out properly and problem is repeatable, turn ignition off and go to next step.
2. Connect 60-pin breakout box to EHCU with ABS adapter cable. Remove fuse No. 29 located in interior
fuse panel. Turn ignition on. Connect voltmeter between ground and breakout box test terminal No. 1.
Observe voltmeter while wiggling circuit. Start at circuit end points or splices and work toward middle.
See WIRING DIAGRAMS
Green wire between EHCU connector and Yellow ABS warning indicator and go to step 4 . If voltage is
not more than zero volt at any time, check fuse, Dark Green wire and/or bulb. Repair as necessary and go
to next step.
3. Turn ignition off. Reinstall fuse No. 29. Connect fused jumper wire between ground and breakout box
test terminal No. 1. Turn ignition on. If Yellow ABS warning indicator comes on brightly, temporarily
substitute a known-good EHCU and go to next step. If warning indicator comes on dimly, replace bulb
and go to next step. If warning indicator does not come on at all and fuse No. 29 is open, repair short to
ground in Dark Green wire and/or replace and go to next step.
4. Using NGS tester, clear all DTCs. Run on-demand selfand step 2) is complete, temporarily substitute a known-good EHCU and retest. If another DTC is
retrieved, go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING
TROUBLE CODES and perform appropriate test. If no DTCs are retrieved, system is functioning
properly.
TEST B: RED BRAKE WARNING INDICATOR FAILURE
NOTE: This test is associated with DTCs C1225 and C1226.
Page 73
clear all DTCs. Disconnect NGS tester. Turn ignition on and observe Red BRAKE warning indicator. If
If DTC is C1225, problem is electrical, go to next step. If DTC is C1226, problem is related to base brake
Ensure ignition is off. Unplug Red brake warning relay located in engine compartment power distribution
. If voltage
. If voltage is more than 10 volts, repair short to voltage in Black/Yellow wire, reconnect
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
warning indicator proves out properly, problem is intermittent, go to INTERMITTENT FAILURES . If
warning indicator comes on continuously and concern is repeatable, go to step 6 . If both warning
indicators are on continuously, go to next step. If Red BRAKE warning indicator never comes on, go to
step 13 .
2.
system, go to step 6 . If both DTC C1225 and C1226 are set, diagnose base brake system first then go to
step 6 .
3.
box. Remove fuse No. 29 located in interior fuse panel. Turn ignition on. Measure voltage between
ground and Red brake warning relay connector terminal No. 4 (Purple/White wire). See Fig. 1
is more than 10 volts, repair short to voltage in Purple/White wire. See WIRING DIAGRAMS . If
voltage is less than 10 volts, go to next step.
4. Measure voltage between ground and Red brake warning relay connector terminal No. 2 (Black/Yellow
wire). See Fig. 1
relay, and go to step 19 . See WIRING DIAGRAMS . If voltage is less than 10 volts, go to next step.
Page 74
Fig. 1: Identifying Red Brake Warning Relay Connector Terminals
reservoir. If fluid level is within limits, go to next step. If fluid level is not within limits, check base brake
Turn ignition on. Measure voltage between ground and Red brake warning relay connector terminal No. 1
. If resistance is less than 5 ohms, repair short to ground in Black/Yellow
Turn ignition on. Measure voltage between ground and Red brake warning relay connector terminal No. 4
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Courtesy of FORD MOTOR CO.
5. Measure resistance between Red brake warning relay terminals No. 1 and 2. See Fig. 1 . If resistance is
50-70 ohms, temporarily substitute a known-good EHCU and go to step 19 . If resistance is not 50-70
ohms, replace relay and go to step 19 .
6. Park vehicle on level surface with parking brake released. Inspect fluid level in brake master cylinder
system for leaks. Repair as necessary and go to step 19 .
7. Ensure ignition is off. Disconnect brake master cylinder reservoir fluid level switch. Turn ignition on. If
Red BRAKE warning indicator is on, go to next step. If warning indicator is not on, replace brake master
cylinder reservoir and go to step 19 .
8. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Connect fused jumper
wire between ground and breakout box test terminal No. 2. Turn ignition on. If Red BRAKE warning
indicator is on, go to step 10 . If warning indicator is not on, go to next step.
9. Turn ignition off. Measure resistance between ground and breakout box test terminal No. 7. If resistance
is less than 10 k/ohms, repair short to ground in Dark Green/Yellow wire between fluid level switch and
EHCU and go to step 19 . If resistance is more than 10 k/ohms, temporarily substitute a known-good
EHCU and go to step 19 .
10. Turn ignition off. Unplug Red brake warning relay located in engine compartment power distribution
box. Turn ignition on. If Red BRAKE warning indicator is on, repair short to ground in Purple/White or
Light Green/Red wire and go to step 19 . See WIRING DIAGRAMS . If warning indicator is not on, go
to next step.
11. Turn ignition off. Measure resistance between breakout box test terminal No. 2 and Red brake warning
relay connector terminal No. 2 (Black/Yellow wire). See Fig. 1 . If resistance is less than 2 ohms, go to
next step. If resistance is more than 2 ohms, repair open in Black/Yellow wire between relay connector
and EHCU and go to step 19 .
12.
(Tan/Red wire). See Fig. 1 . If voltage is more than 10 volts, replace Red brake warning relay and go to
step 19 . If voltage is less than 10 volts, repair open in Tan/Red wire between relay connector and fuse
No. 25. Reconnect relay and go to step 19 . See WIRING DIAGRAMS .
13. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Turn ignition on. If
Red BRAKE warning indicator is on, temporarily substitute a known-good EHCU and go to step 19 . If
warning indicator is not on, go to next step.
14. Turn ignition off. Unplug Red brake warning relay located in engine compartment power distribution
box. Measure resistance between ground and Red brake warning relay connector terminal No. 2
(Black/Yellow wire). See Fig. 1
wire between relay connector and EHCU and go to step 19 . If resistance is more than 5 ohms, go to next
step.
15. Measure resistance between ground and Red brake warning relay connector terminal No. 3 (Black wire).
See Fig. 1 . If resistance is than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in
Black wire between relay connector and ground and go to step 19 .
16.
(Purple/White wire). See Fig. 1 . If voltage is more than 10 volts, replace relay and go to step 19 . If
Page 75
repair open in Purple/White wire between instrument cluster connector and relay connector and go to step
is okay, repair open in Orange/Yellow wire between fuse and EHCU and go to next step. If fuse is blown,
test. Retrieve and record DTCs. If original DTC is
TROUBLE CODE (DTC) INDEX
table under RETRIEVING TROUBLE CODES.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
17. Turn ignition off. Disconnect instrument cluster 12-pin connector. Measure resistance of Purple/White
wire between instrument cluster connector and Red brake warning relay connector terminal No. 4. If
resistance is less than 5 ohms, reconnect relay and go to next step. If resistance is more than 5 ohms,
19 .
18. Remove and check Red BRAKE warning indicator bulb. If bulb is okay, repair instrument cluster as
necessary. If bulb is blown, replace bulb and go to next step.
19. Using NGS tester, clear all DTCs. Turn ignition off then on. Run on-demand self-test. If DTC C1225 is
present, go to step 3 . If DTC C1226 is present, go to step 6 . If a different DTC is present, go to
DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If
no DTCs are present, problem has been corrected.
TEST C: ISOLATION DUMP VALVE
NOTE: This test is associated with DTCs C1194, C1196, C1198, C1200, C1202, C1204,
C1206, C1208, C1212, C1214 and C1216.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Run on-demand self-test. Retrieve and record DTCs. If a single valve DTC is retrieved,
temporarily substitute a known-good EHCU and go to next step. If multiple valve DTCs are retrieved, go
to next step. If no DTCs are retrieved, go to step 4 .
NOTE: A blown fuse may be an indication of some other wiring or component
failure.
2. Turn ignition off. Disconnect EHCU 2-pin connector. Measure voltage between ground and EHCU 2-pin
connector Orange/Yellow wire. If voltage is more than 10 volts, temporarily substitute a known-good
EHCU and go to step 4 . If voltage is less than 10 volts, reconnect EHUC connector and go to next step.
3. Remove and inspect fuse No. 14 (60-amp) located in engine compartment power distribution box. If fuse
replace fuse and/or short to ground in Orange/Yellow wire between fuse and EHCU and go to next step.
4. Using NGS tester, clear all DTCs. Run on-demand selfretrieved, repeat step 1 . If different DTC is retrieved, go to DIAGNOSTIC TROUBLE CODE (DTC)
INDEX table under RETRIEVING TROUBLE CODES. If no DTCs are present, problem has been
corrected.
TEST D: LEFT FRONT WHEEL SPEED SENSOR, STATIC TEST
NOTE: This test is associated with DTC C1155.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Drive vehicle at least 10 MPH. Retrieve DTCs. If DTC C1155 is present, go to next step.
If DTC C1155 is not present, go to step 4 . If different DTC is retrieved, go to DIAGNOSTIC
Page 76
Disconnect left front wheel speed sensor connector. Measure resistance between terminals of wheel speed
FAILURES. If sensor passed test, reconnect sensor and go to next step. If sensor did not pass test, replace
. If different DTC is retrieved,
damage and/or missing teeth. Rotate ring to be sure all teeth are checked. If sensor ring is damaged or has
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
2. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance
between breakout box test terminals No. 11 and 23. On 2WD vehicles, resistance should be 2000-4000
ohms. On 4WD vehicles, resistance should be 300-500 ohms. If resistance is as specified, go to step 4 . If
resistance is less than specified, replace left front wheel speed sensor and go to step 7 . If resistance is
more than specified, go to next step.
3.
sensor. If resistance is more than 4000 ohms on 2WD vehicles or more than 500 ohms on 4WD vehicles,
replace left front wheel speed sensor and go to step 7 . If resistance is less than 4000 ohms on 2WD
vehicles or less than 500 ohms on 4WD vehicles, repair Tan/Black wire and/or Tan/Orange wire and go
to step 7 . See WIRING DIAGRAMS .
4. Measure resistance between ground and breakout box test terminals No. 11 and 23. If resistance is less
than 100 k/ohms, go to next step. If resistance is more than 100 k/ohms, go to step 6 .
5. Disconnect left front wheel speed sensor connector. Measure resistance between ground and each
terminal of wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel speed sensor and go
to step 7 . If resistance is more than 100 k/ohms, repair Tan/Black wire and/or Tan/Orange wire and go to
step 7 .
6. Conduct SENSOR FAILURE TEST for left front wheel speed sensor under INTERMITTENT
sensor and go to next step.
7. Turn ignition off. Using NGS tester, clear all DTCs. Test drive vehicle over rough road. Perform ondemand self-test. Retrieve DTCs. If original DTC is retrieved, repeat step 1
go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE
CODES. If no DTC is retrieved, repair is complete.
TEST E: LEFT FRONT WHEEL SPEED SENSOR, DYNAMIC TEST
CAUTION: Turn air suspension (if equipped) off before hoisting, jacking or towing
vehicle. Air suspension switch is located on right kick panel. Failure to do
so may result in unexpected inflation or deflation of air springs which may
result in shifting of the vehicle.
NOTE: This test is associated with DTCs C1158 and C1233.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
retrieve all DTCs. If DTC C1155 is retrieved, diagnose DTC C1155 first. Ignore all other DTCs. If DTC
C1155 is not retrieved, go to next step.
NOTE: Some variation between all 3 sensors is expected on hard turns.
2. Using NGS tester, monitor all 3 wheel speed sensors while driving vehicle at various speeds. If left front
wheel speed sensor consistently matches other 2 sensors, go to step 7 . If left front wheel speed sensor
does not match other 2 sensors, go to next step.
3. Turn air suspension off (if equipped). Raise vehicle on hoist. Carefully inspect left front sensor ring for
Page 77
missing teeth, replace ring and go to step
9
. If sensor ring is okay, go to next step.
Turn ignition off. Disconnect left front wheel speed sensor connector. Measure resistance between ground
and each terminal of wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel speed sensor
2WD vehicles or less than 500 ohms on 4WD vehicles, repair Yellow/Red wire and/or Yellow/Black wire
than 100 k/ohms, go to next step. If resistance is more than 100 k/ohms, go to step
6
.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
4. Wiggle wheel speed sensor at wheel end. If any looseness is detected, tighten sensor to 63-80 INCH lbs.
(7-9 N.m). Go to step 9 . If sensor is not loose, go to next step.
5.
and go to step 9 . If resistance is more than 100 k/ohms, go to next step.
6. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance between breakout
box test terminals No. 11 and 23. If resistance is less than 100 k/ohms, repair short to ground in
Tan/Black and/or Tan/Orange wire and go to step9 . See WIRING DIAGRAMS . If resistance is more
than 100 k/ohms. go to next step.
7. Turn ignition off. Conduct SENSOR FAILURE TEST for left front wheel speed sensor under
INTERMITTENT FAILURES. If sensor passed test, reconnect sensor and go to step 9 . If sensor did not
pass test, replace sensor and go to next step.
8. Remove left front wheel speed sensor. Inspect sensor housing for stress cracks or breaks. Inspect sensor
connector for evidence of water entry, pin corrosion or excessive debris. If any condition is present,
correct condition as necessary and go to next step. If sensor and connector are okay, reconnect sensor and
go to next step.
9. Disconnect breakout box and reactivate air suspension (if equipped). Using NGS tester, clear all codes.
Turn ignition off and on. Drive vehicle completing at least one hard left and one hard right turn. Travel
over rough road at normal speed. Perform one hard and normal acceleration from dead stop. Retrieve
DTCs. If original DTC is retrieved, go to step 2 . If a different DTC is retrieved, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If no DTC is
retrieved, repair is complete.
TEST F: RIGHT FRONT WHEEL SPEED SENSOR, STATIC TEST
NOTE: This test is associated with DTC C1145.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Drive vehicle at least 10 MPH. Retrieve DTCs. If DTC C1145 is present, go to next step.
If DTC C1145 is not present, go to step 6 . If different DTC is retrieved, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES.
2. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance
between breakout box test terminals No. 10 and 22. On 2WD vehicles, resistance should be 2000-4000
ohms. On 4WD vehicles, resistance should be 300-500 ohms. If resistance is as specified, go to step 4 . If
resistance is less than specified, replace left front wheel speed sensor and go to step 7 . If resistance is
more than specified, go to next step.
3. Disconnect right front wheel speed sensor connector. Measure resistance between terminals of wheel
speed sensor. If resistance is more than 4000 ohms on 2WD vehicles or more than 500 ohms on 4WD
vehicles, replace left front wheel speed sensor and go to step 7 . If resistance is less than 4000 ohms on
and go to step 7 . See WIRING DIAGRAMS .
4. Measure resistance between ground and breakout box test terminals No. 10 and 22. If resistance is less
Page 78
FAILURES. If sensor passed test, reconnect sensor and go to next step. If sensor did not pass test, replace
. If different DTC is retrieved,
Using NGS tester, monitor all 3 wheel speed sensors while driving vehicle at various speeds. If right front
damage and/or missing teeth. Rotate ring to be sure all teeth are checked. If sensor ring is damaged or has
INTERMITTENT FAILURES. If sensor passed test, reconnect sensor and go to step
9
. If sensor did not
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
5. Disconnect right front wheel speed sensor connector. Measure resistance between ground and each
terminal of wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel speed sensor and go
to step 7 . If resistance is more than 100 k/ohms, repair Yellow/Red wire and/or Yellow/Black wire and
go to step 7 .
6. Conduct SENSOR FAILURE TEST for right front wheel speed sensor under INTERMITTENT
sensor and go to next step.
7. Turn ignition off. Using NGS tester, clear all DTCs. Test drive vehicle over rough road. Perform ondemand self-test. Retrieve DTCs. If original DTC is retrieved, repeat step 1
go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE
CODES. If no DTC is retrieved, repair is complete.
TEST G: RIGHT FRONT WHEEL SPEED SENSOR, DYNAMIC TEST
CAUTION: Turn air suspension (if equipped) off before hoisting, jacking or towing
vehicle. Air suspension switch is located on right kick panel. Failure to do
so may result in unexpected inflation or deflation of air springs which may
result in shifting of the vehicle.
NOTE: This test is associated with DTCs C1148 and C1234.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
retrieve all DTCs. If DTC C1145 is retrieved, diagnose DTC C1145 first. Ignore all other DTCs. If DTC
C1145 is not retrieved, go to next step.
NOTE: Some variation between all 3 sensors is expected on hard turns.
2.
wheel speed sensor consistently matches other 2 sensors, go to step 7 . If right front wheel speed sensor
does not match other 2 sensors, go to next step.
3. Turn air suspension off (if equipped). Raise vehicle on hoist. Carefully inspect right front sensor ring for
missing teeth, replace ring and go to step 8 . If sensor ring is okay, go to next step.
4. Wiggle wheel speed sensor at wheel end. If any looseness is detected, tighten wheel speed sensor to 6380 INCH lbs. (7-9 N.m) and go to step 9 . If sensor is not loose, go to next step.
5. Turn ignition off. Disconnect right front wheel speed sensor connector. Measure resistance between
ground and each terminal of wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel
speed sensor and go to step 9 . If resistance is more than 100 k/ohms, go to next step.
6. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance between breakout
box test terminals No. 10 and 22. If resistance is less than 100 k/ohms, repair short to ground in
Yellow/Red wire and/or Yellow/Black wire and go to step 9 . See WIRING DIAGRAMS . If resistance
is more than 100 k/ohms. go to next step.
7. Turn ignition off. Conduct SENSOR FAILURE TEST for right front wheel speed sensor under
Page 79
pass test, replace sensor and go to next step.
. If different DTC is retrieved,
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
8. Remove right front wheel speed sensor. Inspect sensor housing for stress cracks or breaks. Inspect sensor
connector for evidence of water entry, pin corrosion or excessive debris. If any condition is present,
correct condition as necessary and go to next step. If sensor and connector are okay, reconnect sensor and
go to next step.
9. Disconnect breakout box and reactivate air suspension (if equipped). Using NGS tester, clear all codes.
Turn ignition off and on. Drive vehicle completing at least one hard left and one hard right turn. Travel
over rough road at normal speed. Perform one hard and normal acceleration from dead stop. Retrieve
DTCs. If original DTC is retrieved, go to step 2 . If a different DTC is retrieved, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If no DTC is
retrieved, repair is complete.
TEST H: REAR WHEEL SPEED SENSOR, STATIC TEST
NOTE: This test is associated with DTC C1230.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Drive vehicle at least 10 MPH. Retrieve DTCs. If DTC C1230 is present, go to next step.
If DTC C1230 is not present, go to step 6 . If different DTC is retrieved, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES.
2. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance
between breakout box test terminals No. 9 and 21. If resistance is 900-1500 ohms, go to step 4 . If
resistance is less than 900 ohms, replace rear wheel speed sensor and go to step 7 . If resistance is more
than 1500 ohms, go to next step.
3. Disconnect rear wheel speed sensor connector. Measure resistance between terminals of wheel speed
sensor. If resistance is more than 1500 ohms, replace rear wheel speed sensor and go to step 7 . If
resistance is less than 900 ohms, repair Light Green/Black wire and/or Red/Pink wire and go to step 7 .
See WIRING DIAGRAMS .
4. Measure resistance between ground and breakout box test terminals No. 9 and 21. If resistance is less
than 100 k/ohms, go to next step. If resistance is more than 100 k/ohms, go to step 6 .
5. Disconnect rear wheel speed sensor connector. Measure resistance between ground and each terminal of
wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel speed sensor and go to step 7 . If
resistance is more than 100 k/ohms, repair Light Green/Black wire and/or Red/Pink wire and go to step
7 .
6. Conduct SENSOR FAILURE TEST for rear wheel speed sensor under INTERMITTENT FAILURES.
If sensor passed test, reconnect sensor and go to next step. If sensor did not pass test, replace sensor and
go to next step.
7. Turn ignition off. Using NGS tester, clear all DTCs. Test drive vehicle over rough road. Perform ondemand self-test. Retrieve DTCs. If original DTC is retrieved, repeat step 1
go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE
CODES. If no DTC is retrieved, repair is complete.
TEST J: REAR WHEEL SPEED SENSOR, DYNAMIC
Page 80
. If rear wheel speed sensor does not
damage and/or missing teeth. Rotate ring to be sure all teeth are checked. If sensor ring is damaged or has
21 ft. lbs.
each terminal of wheel speed sensor. If resistance is less than 100 k/ohms, replace wheel speed sensor and
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
CAUTION: Turn air suspension off (if equipped) before hoisting, jacking or towing
vehicle. Air suspension switch is located on right kick panel. Failure to do
so may result in unexpected inflation or deflation of air springs which may
result in shifting of the vehicle.
NOTE: This test is associated with DTCs C1229 and C1237.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
retrieve all DTCs. If DTC C1230 is retrieved, diagnose DTC C1230 first. Ignore all other DTCs. If DTC
C1230 is not retrieved, go to next step.
NOTE: Some variation between all 3 sensors is expected on hard turns.
2. Using NGS tester, monitor all 3 wheel speed sensors while driving vehicle at various speeds. If rear
wheel speed sensor consistently matches other 2 sensors, go to step 7
match other 2 sensors, go to next step.
3. Turn air suspension off (if equipped). Raise vehicle on hoist. Carefully inspect rear sensor ring for
missing teeth, replace ring and go to step 9 . If sensor ring is okay, go to next step.
4. Wiggle wheel speed sensor at differential case. If any looseness is detected, tighten sensor to 18(25-29 N.m) and go to step 9 . If sensor is not loose, go to next step.
5. Turn ignition off. Disconnect rear wheel speed sensor connector. Measure resistance between ground and
go to step 9 . If resistance is more than 100 k/ohms, go to next step.
6. Connect 60-pin breakout box to EHCU with ABS adapter cable. Measure resistance between breakout
box test terminals No. 9 and 21. If resistance is less than 100 k/ohms, repair short to ground in Light
Green/Black wire and/or Red/Pink wire and go to step 9 . If resistance is more than 100 k/ohms. go to
next step.
7. Turn ignition off. Conduct SENSOR FAILURE TEST for rear wheel speed sensor under
INTERMITTENT FAILURES. If sensor passed test, reconnect sensor and go to step 9 . If sensor did not
pass test, go to next step.
8. Remove rear wheel speed sensor. Inspect sensor housing for stress cracks or breaks. Inspect sensor
connector for evidence of water entry, pin corrosion or excessive debris. If any condition is present,
correct condition as necessary and go to next step. If sensor and connector are okay, reconnect sensor and
go to next step.
9. Disconnect breakout box and reactivate air suspension (if equipped). Using NGS tester, clear all codes.
Turn ignition off and on. Drive vehicle completing at least one hard left and one hard right turn. Travel
over rough road at normal speed. Perform one hard and normal acceleration from dead stop. Retrieve
DTCs. If original DTC is retrieved, go to step 2 . If a different DTC is retrieved, go to DIAGNOSTIC
TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If no DTC is
retrieved, repair is complete.
TEST K: SOFT/EXCESSIVE PEDAL TRAVEL
Page 81
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
NOTE: This test is not associated with any DTC.
1. Visually inspect brakelines from EHCU to each wheel cylinder. Visually inspect calipers and brake
components. If any damage is found, replace and/or repair as necessary and go to SYSTEM
PRECHECK . If no damage is found, go to next step.
NOTE: A leaky dump valve is similar to a master cylinder bypass condition. Press
brake pedal quickly and forcefully to rule out master cylinder bypass.
2. Remove rubber boots from EHCU Low Pressure Accumulators (LPA). Insert clean paper clip into each
LPA port. See Fig. 2 . Have an assistant press hard on brake pedal while observing paper clips. If any of
the paper clips move significantly, replace EHCU. If paper clips do not move significantly, remove paper
clips, reinstall rubber boots and go to next step.
Fig. 2: Checking Dump Valves For Leakage
Courtesy of FORD MOTOR CO.
3. Remove fuse No. 14 (60-amp) located in engine compartment power distribution box. Test drive vehicle
at about 20 MPH. Perform light to medium (normal) traffic stop. If any one wheel locks consistently, go
Page 82
PRECHECK
.
RETRIEVING TROUBLE CODES. If no DTCs are retrieved, repair is complete.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
TEST L: PUMP MOTOR
NOTE: This test is associated with DTCs C1095 and C1096.
1. Verify ABS pump motor pigtail is connected to ABS control module. Connect New Generation Star
(NGS) tester, following manufacturer's instructions. Using NGS tester, clear all DTCs. Run on-demand
self-test. Retrieve DTCs. If DTC C1095 is retrieved, temporarily substitute a known-good EHCU and
retest. If DTC C1096 is retrieved, go to next step. If no DTCs are retrieved, go to step 4 . If a different
DTC is retrieved, go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING
TROUBLE CODES.
2. Turn ignition off. Disconnect 2-pin EHCU harness connector. Measure voltage between ground and
EHCU 2-pin harness connector Orange/Yellow wire. If voltage is more than 10 volts, go to next step. If
voltage is less than 10 volts, repair open in Orange/Yellow wire between EHCU and fuse No. 14 (60amp) located in engine compartment power distribution box, reconnect EHCU and go to step 4 .
3. Measure resistance between ground and EHCU 2-pin harness connector Light Green/Yellow wire. If
resistance is more than one ohm, repair open in Light Green/Yellow wire between EHCU and ground
located at left front radiator support, reconnect EHCU and go to next step. If resistance is less than one
ohm, temporarily substitute a known-good EHCU and go to next step.
4. Using NGS tester, clear all DTCs. Drive vehicle over rough road and through car wash. Run on-demand
self-test. Retrieve DTCs. If original DTC is retrieved, go to step 1 . If different DTC is retrieved, go to
DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If
no DTCs are retrieved, repair is complete.
TEST M: INTERNAL POWER RELAY
NOTE: This test is associated with DTCs C1113, C1115 and C1185.
1. Connect New Generation Star (NGS) tester, following manufacturer's instructions. Using NGS tester,
clear all DTCs. Run on-demand self-test. Retrieve DTCs. If DTC C1113 or C1115 is retrieved,
temporarily substitute a known-good EHCU and go to step 4 . If DTC C1185 is retrieved, go to next step.
If no DTCs are retrieved, go to step 4 .
2. Turn ignition off. Remove and inspect fuse No. 14 (60-amp) located in engine compartment power
distribution box. If fuse is okay, go to next step. If fuse is blown, replace fuse and/or repair short to
ground in Orange/Yellow wire between EHCU and fuse No. 14 and go to step 4 .
3. Reinstall fuse No. 14. Disconnect 2-pin EHCU harness connector. Measure voltage between ground and
EHCU 2-pin harness connector Orange/Yellow wire. If voltage is more than 10 volts, temporarily
substitute a known-good EHCU and go to next step. If voltage is less than 10 volts, repair open in
Orange/Yellow wire between fuse No. 14 and EHCU and go to next step.
4. Using NGS tester, clear all DTCs. Turn ignition off. Drive vehicle over rough road and through car wash.
If fault is repeatable, run on-demand self-test. Retrieve DTCs. If original DTC is retrieved, go to step 2 .
If different DTC is retrieved, go to DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under
Page 83
TEST N: NO MODULE COMMUNICATIONS
inspect tires for mismatched sizes. Inspect sensor rings for damage. If inspections are normal, temporarily
. If a different DTC is retrieved, go to
repeat
.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
NOTE: This test is not associated with any DTCs.
1. Turn ignition off. Connect New Generation Star (NGS) tester, following manufacturer's instructions.
Using NGS tester, retrieve DTCs. If DTCs are obtained, go to SYSTEM PRECHECK step 4). If no
DTCs are obtained, go to next step.
2. Turn ignition off. Connect 60-pin breakout box to EHCU with ABS adapter cable. Turn ignition on.
Measure voltage between ground and breakout box test terminal No. 14. If voltage is more than 10 volts,
go to next step. If voltage is less than 10 volts, replace fuse No. 25 (5-amp) located in interior fuse panel
and/or repair short in Tan/Red wire between fuse No. 25 and 4WABS relay located in engine
compartment power distribution box.
3. Turn ignition off. Disconnect negative battery cable. Measure resistance between ground and breakout
box test terminal No. 2. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms,
repair open in Light Green/Yellow wire between EHCU and ground located at left front radiator support
and go to next step.
4. Measure resistance between breakout box test terminal No. 5 and Data Link Connector (DLC) Light
Blue/White wire. If resistance is less than 5 ohms, temporarily substitute a known-good EHCU and go to
SYSTEM PRECHECK step 4). If resistance is more than 5 ohms, repair open in Light Blue/White wire
between EHCU and DLC and go to SYSTEM PRECHECK step 4).
TEST P: ABS SYSTEM TIME OUT/WHEEL SPEED SENSOR ERROR, DYNAMIC
NOTE: This test is associated with DTCs C1184 and C1222.
1. Turn ignition off. Connect New Generation Star (NGS) tester, following manufacturer's instructions.
Using NGS tester, clear all DTCs. Drive vehicle at various speeds. Using NGS tester, retrieve DTCs. If
DTC C1184 is retrieved and ABS does not activate during normal stops, temporarily substitute a knowngood EHCU and recheck. If ABS activates on normal stops, go to next step. If DTC C1222 is retrieved,
substitute a known-good EHCU and go to SYSTEM PRECHECK
DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If
no DTCs are retrieved, repeat SYSTEM PRECHECK .
NOTE: When monitoring wheel speed signals, monitor one wheel at a time.
Information will be recorded faster and likelihood of diagnosing faulty
signal is greater.
2. Clear all DTCs. Monitor wheel speeds while driving vehicle at various speeds. If one wheel speed signal
drops out while driving or braking, go to appropriate WHEEL SPEED SENSOR, DYNAMIC TEST. See
DIAGNOSTIC TROUBLE CODE (DTC) INDEX table under RETRIEVING TROUBLE CODES. If
one wheel speed signal does not drop out while driving or braking, repeat monitoring as intermittent
signals may not be recorded the first time. Inspect sensor rings and sensor wiring for damage and repair
as necessary. In no damage is found, go to INTERMITTENT FAILURES to test suspect sensor and
SYSTEM PRECHECK
Page 84
TEST R: EXCESSIVE DUMP TIME
wire and negative battery cable. Observe voltmeter while wiggling wiring between power distribution box
Wiggle wiring harness at several points between EHCU and instrument cluster. Repair/replace wiring harness at
location that warning indicator flickered off indicating an open circuit.
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
NOTE: This test is associated with DTC C1169.
1. Turn ignition off. Connect New Generation Star (NGS) tester, following manufacturer's instructions.
Using NGS tester, clear all DTCs. Retrieve DTCs. If DTC C1169 is retrieved, temporarily substitute a
known-good EHCU and go to SYSTEM PRECHECK . If DTC C1169 is not retrieved, go to next step.
NOTE: Wet down area where stop is to be preformed. Have an assistant monitor
wheels during ABS stop. Momentary lock-up is permissible.
2. Drive vehicle at about 10 MPH. Apply brakes hard enough to lock all 4 wheels. If one wheel locks-up
consistently, go to ABS MISFIRE under SYMPTOM DIAGNOSIS . If one wheel does not lock-up
consistently, go to SYSTEM PRECHECK .
INTERMITTENT FAILURES
EHCU POWER & GROUND TEST
Fuse Failure
If fuse has failed, check weather packing for 2-pin EHCU connector. Remove fuse No. 14 (60-amp) located in
engine compartment power distribution box. Connect an ohmmeter between ground and outside pin of fuse
connector (Orange/Yellow wire). Spray with water and wiggle wiring between power distribution box and
EHCU. If any continuity is observed, repair/replace wiring as necessary.
Check For Open Circuit In Wiring
1. Disconnect 2-pin EHCU connector. Connect a voltmeter between EHCU 2-pin connector Orange/Yellow
and EHCU. If voltage momentarily drops below 10 volts while harness is wiggled, repair/replace wiring
as necessary.
2. Connect an ohmmeter between ground and 2-pin EHCU connector Light Green/Yellow wire. Observe
ohmmeter while wiggling wiring between EHCU connector and ground located at left front radiator
support. If resistance momentarily goes above 5 ohms while wiggling harness, repair/replace wiring as
necessary.
INDICATOR FAILURE TEST
No Prove Out
Connect 60-pin breakout box to EHCU with ABS adapter cable. Connect breakout box test terminal No. 1 (for
Yellow ABS warning indicator) or No. 4 (for Red BRAKE warning indicator) to ground. Turn ignition on.
Page 85
Indicator Always On
table. If resistance does not
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
With ignition on, wiggle wiring harness at several points between EHCU and instrument cluster. Repair/replace
wiring harness at location that warning indicator flickered on indicating a short to ground.
SENSOR FAILURE TEST
NOTE: A digital multimeter with minimum/maximum hold feature is required for the
following tests.
Check For Short To Ground
1. Connect 60-pin breakout box to EHCU with ABS adapter cable. Disconnect suspect sensor. Enable
minimum resistance hold feature.
2. For left front wheel speed sensor, monitor resistance between ground and breakout box test terminals No.
11 (Tan/Orange wire) and No. 23 (Tan/Black wire). Drive vehicle over rough roads at various speeds. If
there is continuity between either circuit and ground, repair circuit for short to ground.
3. For right front wheel speed sensor, monitor resistance between ground and breakout box test terminals
No. 10 (Yellow/Red wire) and No. 22 (Yellow/Black wire). Drive vehicle over rough roads at various
speeds. If there is continuity between either circuit and ground, repair circuit for short to ground.
4. For rear wheel speed sensor, monitor resistance between ground and breakout box test terminals No. 9
(Red/Pink wire) and No. 21 (Light Green/Black wire). Drive vehicle over rough roads at various speeds.
If there is continuity between either circuit and ground, repair circuit for short to ground.
Check For Open Circuit
1. Connect 60-pin breakout box to EHCU with ABS adapter cable. Disconnect suspect sensor and connect
jumper wire between sensor harness connector terminals. Enable maximum resistance hold feature.
2. For left front wheel speed sensor, monitor resistance between breakout box test terminals No. 11
(Tan/Orange wire) and No. 23 (Tan/Black wire). Drive vehicle over rough roads at various speeds. If
there is an open between either circuit, repair circuit for an open.
3. For right front wheel speed sensor, monitor resistance between breakout box test terminals No. 10
(Yellow/Red wire) and No. 22 (Yellow/Black wire). Drive vehicle over rough roads at various speeds. If
there is an open between either circuit, repair circuit for open.
4. For rear wheel speed sensor, monitor resistance between breakout box test terminals No. 9 (Red/Pink
wire) and No. 21 (Light Green/Black wire). Drive vehicle over rough roads at various speeds. If there is
an open between either circuit, repair circuit for open.
Check Sensor Pigtail
1. Enable maximum resistance hold feature. Monitor resistance between suspect wheel speed sensor
terminals while wiggling pigtail. See SENSOR MAXIMUM RESISTANCE
remain within specification, replace sensor.
SENSOR MAXIMUM RESISTANCE
Page 86
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Sensor Resistance (Ohms)
Front
2WD 4000
4WD 500
Rear 1500
2. Enable minimum resistance hold feature. Monitor resistance between suspect wheel speed sensor
terminals while wiggling pigtail. See SENSOR MINIMUM RESISTANCE table. If resistance does not
remain within specification, replace sensor.
SENSOR MINIMUM RESISTANCE
Sensor Resistance (Ohms)
Front
2WD 2000
4WD 300
Rear 900
3. Monitor resistance between ground and suspect wheel speed sensor terminals while wiggling pigtail. If
meter indicates anything but an open circuit, replace sensor.
REMOVAL & INSTALLATION
CAUTION: When battery is disconnected, vehicle computer and memory systems
may lose memory data. Driveability problems may exist until computer
systems have completed a relearn cycle. See COMPUTER RELEARN
PROCEDURES article in the GENERAL INFORMATION section before
disconnecting battery. Vehicle may need to be driven more than 10 miles
to relearn strategy.
ELECTRONIC CONTROL MODULE (ECM)
CAUTION: If replacing ABS ECM, ensure correct model application is identified on
ECU identification sticker.
Removal & Installation
Disconnect negative battery cable. Disconnect ABS ECM harness connectors. Disconnect pump motor
electrical connector from bottom of ABS ECM. Remove 4 ABS ECM screws and remove ECM. To install,
reverse removal procedure. Tighten ECM screws to specification. See TORQUE SPECIFICATIONS .
HYDRAULIC CONTROL UNIT (HCU)
CAUTION: Plug each open port and pipe to prevent brake fluid from spilling.
Page 87
Disconnect and plug 2 inlet and 3 outlet brakelines from HCU. Remove HCU mounting bolts and remove
wheel speed sensor attaching bolt and remove sensor. To install, reverse removal procedure. Tighten sensor bolt
Remove 2 wheel speed sensor attaching bolts and remove sensor. To install, reverse removal procedure. Tighten
jaw puller, remove sensor ring from hub. Discard old sensor
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Removal & Installation
1. Disconnect negative battery cable. Disconnect ABS ECM harness connectors. Disconnect pump motor
electrical connector from bottom of ABS ECM. Remove 4 ABS ECM screws and remove ECM.
HCU.
2. To install reverse removal procedure. Tighten bolts, screws and brakeline fittings to specification. See
TORQUE SPECIFICATIONS . Bleed brakes and EHCU. See BLEEDING BRAKE SYSTEM .
FRONT WHEEL SPEED SENSOR
Removal & Installation (2WD)
Disconnect front wheel speed sensor harness connector. Separate sensor pigtail from brake hose clips. Remove
to specification. See TORQUE SPECIFICATIONS .
Removal & Installation (4WD)
Disconnect front wheel speed sensor harness connector. Remove front disc brake caliper, rotor and rotor shield.
sensor bolts to specification. See TORQUE SPECIFICATIONS .
REAR WHEEL SPEED SENSOR
CAUTION: Remove all dirt from rear axle mounting surface and sensor to prevent
contamination of rear axle lubricant.
Removal & Installation
Disconnect rear wheel speed sensor harness connector. Remove sensor mounting bolt and remove sensor. To
install, clean axle mounting surface. Inspect and clean magnetized sensor pole piece. Inspect sensor "O" ring
and replace as necessary. Light lubricate "O" ring with engine oil and install sensor in axle housing. Tighten
mounting bolt to specification. See TORQUE SPECIFICATIONS .
FRONT SENSOR RING
Removal & installation (2WD)
Remove front disc brake caliper and rotor. Using 3ring. To install, position new sensor ring on hub. Using an appropriate size cylinder and press, install sensor
ring on hub. To complete installation, reverse removal procedure.
Removal & Installation (4WD)
Page 88
Front sensor ring is an integral part of hub and must be replaced as an assembly.
Rear sensor ring is incorporated into rear differential. See appropriate differentials article in the DRIVE AXLES
WIRING DIAGRAMS
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
REAR SENSOR RING
Removal & Installation
section.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
Application Ft. Lbs. (N.m)
Brakeline Fittings
1/2 - 20 15-21 (21-29)
7/16 - 24 11-15 (15-20)
EHCU Bracket Bolts 13-13 (17-23)
EHCU Mounting Bolts 22-30 (30-40)
Rear Wheel Speed Sensor Bolt 25-30 (34-40)
INCH Lbs. (N.m)
Control Module Screws 35-44 (4-5)
Front Wheel Speed Sensor Bolt 63-80 (7-9)
Page 89
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Page 90
Fig. 3: Anti
-
Lock Brake System Wiring Diagram (Expedition)
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Page 91
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Page 92
Fig. 4: Anti
-
Lock Brake System Wiring Diagram (F150/250 Pickup)
1997 Ford Pickup F150
ANTI-LOCK BRAKE SYSTEM - 4-WHEEL 1997 BRAKES Ford Motor Co. - Anti-Lock - 4WAL
Page 93
1997 ANTI
-
LOCK BRAKE SYSTEM
SYSTEM DIODE/RESISTOR
1997 Ford Pickup F150
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
Anti-Lock - RABS II - "F" Series Pickup
DESCRIPTION & OPERATION
CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in the GENERAL
INFORMATION section.
NOTE: For more information on brake system, see BRAKE SYSTEM article in the
BRAKES section.
The Rear Anti-Lock Brake System II (RABS II) is designed to prevent rear brake lock-up by controlling
hydraulic fluid pressure to the rear wheel cylinders. The system consists of 2 warning lights (Red BRAKE and
Yellow ABS), an anti-lock electronic control unit, an electrohydraulic RABS valve, stoplight switch, fluid level
sensor, speed sensor and exciter ring.
ABS CONTROL MODULE
The ABS control module continuously monitors rear (axle mounted) wheel speed sensor input. It compares the
rate of deceleration with programed normal stopping distance. If impending lock-up occurs, the control module
energizes the RABS valve.
RABS VALVE
The RABS valve contains an isolation and a dump valve operated by solenoids controlled by the ABS control
module. The isolation valve prevents additional pressure from being fed to rear brake system and dump valve
releases pressure from rear brake system.
The RABS valve will store "dumped" brake fluid until brake pressure is released and then releases it back to
brake master cylinder reservoir.
RABS SELF-TEST CAPABILITY
The anti-lock electronic control module performs a system test during start-up and normal operation. Red
BRAKE warning light indicates low fluid level, parking brake applied or low vacuum (diesel models). If a
problem is detected, the control module will be deactivated and a Yellow ABS warning light will be
illuminated. Both warning lights should come on for about 2 seconds when ignition is turned on or when
cranking engine.
When Yellow ABS warning light illuminates during normal operation, the system has detected a problem and
stored a trouble code. Loss of power to control module will cause system to be deactivated and Yellow ABS
light to be illuminated, but will not set a trouble code.
Page 94
System diode together with an associated resistor are used to prevent a false Code 12 from being set when
disconnected or master cylinder has run dry, bleed master cylinder and brakes at all 4 wheels. Bleed brakes with
free
3.
Repeat procedure until air is completely purged from master cylinder. When all air has escaped, tighten
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
parking brake is applied.
BLEEDING BRAKE SYSTEM
Hydraulic system bleeding is necessary whenever air enters system. If master cylinder lines have been
pressure bleeding equipment or by pumping brake pedal. Always bleed brakelines in sequence. See
BLEEDING SEQUENCE.
MANUAL BLEEDING
CAUTION: DO NOT allow reservoir to run dry during bleeding operation. If brake fluid
is spilled onto vehicle paint, rinse off immediately using water.
Master Cylinder Bleeding (On Vehicle)
1. Using a line wrench, remove front brake line and master cylinder rear outlet brake line from master
cylinder. Install short tubes in master cylinder and position them so they curve into master cylinder
reservoir, and ends of tubes are submerged in brake fluid.
2. Fill master cylinder reservoir with new brake fluid. Have an assistant pump brakes until clear, bubblefluid flows from both brake tubes. Remove short brake tubes and reinstall front brake line and master
cylinder rear outlet line on master cylinder. Bleed each brake line at master cylinder by having and
assistant pump brake pedal 10 times and then hold firm pressure on brake pedal.
3. Loosen rear-most brake line fittings until a stream of brake fluid comes out. Have an assistant maintain
pressure on brake pedal until brake line fitting is tightened again. Repeat procedure until clear, bubblefree fluid comes out from around fitting. Refill master cylinder reservoir as necessary. Repeat this
bleeding operation at front brake line fittings.
Gravity Bleeding
Fill brake master cylinder with new brake fluid. Loosen both wheel cylinder bleeder screws and leave them
open until clear brake fluid flows. Be sure to check master cylinder reservoir fluid level often and do not let it
run dry. Tighten wheel cylinder bleeder screws. One at a time, loosen caliper bleeder screws. Leave bleeder
screws open until clear fluid flows. Check fluid level often. Tighten caliper bleeder screws.
Manual Bleeding
1. Clean master cylinder cap and surrounding area. Remove cap. Vehicles are equipped with dual-type
master cylinder. Bleed primary and secondary systems separately. Loosen primary or secondary master
cylinder hydraulic line fitting.
2. Wrap a shop towel around brake lines to absorb escaping brake fluid. Slowly push brake pedal down to
force out air. With pedal fully depressed, tighten fittings to prevent air from being sucked into master
cylinder when pedal is released. Release brake pedal.
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fittings with pedal down. Release pedal, and depress again. If pedal is not firm, repeat bleeding
BLEEDING SEQUENCE
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
procedure.
4. Repeat procedure at bleeder fitting on RABS electrohydraulic valve (if equipped), each wheel cylinder
and caliper. See BLEEDING SEQUENCE table under BLEEDING SEQUENCE. When bleeding is
complete, fill master cylinder to proper level.
PRESSURE BLEEDING
NOTE: The use of ABS Bleeder Box Adapter (T90P-50-ALA) and Jumper (T93T-50-ALA)
is required in conjunction with pressure bleeding to bleed system when
Hydraulic Control Unit (HCU) is replaced.
1. Clean master cylinder cap and surrounding area. Remove cap. With pressure tank at least 1/2 full of
specified brake fluid and charged between 10-30 psi (.7-2.0 kg/cm2 ), use adapters to connect tank to
master cylinder. Follow equipment manufacturer's instructions.
CAUTION:
Never exceed 50 psi (3.5 kg/cm2 ) during bleeding.
2. Open pressure bleeder valve. Bleed master cylinder primary and secondary hydraulic lines individually.
Put shop towels in place to catch brake fluid.
3. Open lines and allow brake fluid to flow out until all air is purged. Close bleed fitting and hydraulic line.
Close pressure bleeder valve. Attach rubber drain hose to first wheel cylinder bleeder valve to be
serviced. See BLEEDING SEQUENCE table under BLEEDING SEQUENCE.
4. Place other end of hose in clean glass jar partially filled with clean brake fluid so end of hose is
submerged in fluid. Open pressure bleeder valve. Open bleeder fitting. Close bleeder fitting when fluid
flow is free of bubbles. Repeat procedure on remaining wheel cylinder and calipers in sequence. See
BLEEDING SEQUENCE.
5. When bleeding operation is complete, close pressure bleeder valve, and remove tank hose from adapter
fitting. Check brake pedal operation. Ensure master cylinder is full of fluid.
SERVICE TOOL BLEEDING
NOTE: The use of ABS Bleeder Box Adapter (T90P-50-ALA) and Jumper Cable (T93T-
50-ALA) is required in conjunction with pressure bleeding, to bleed system
when Hydraulic Control Unit (HCU) is replaced.
1. Connect ABS Bleeder Box Adapter (T90P-50-ALA) and Jumper Cable (T93T-50-ALA) to HCU.
2. Depress brake pedal and depress VALVES button on bleeder box adapter. Brake pedal height should
drop. Release VALVES button and release brake pedal.
3. Repeat step 2) one more time. Depress MOTOR START button allow pump motor to operate for one
minute, then proceed with pressure bleeding the brake system. See BLEEDING BRAKE SYSTEM.
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Before bleeding system, remove all vacuum from power unit by depressing brake pedal several times. Bleed
running lights on. Block front and rear wheels to prevent vehicle from moving. Release parking brake.
have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES
On Wiring Harness, At
Under Right Side Of Dash, Near
Threaded Into Front Of
On Firewall, Above Master
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
master cylinder first, followed in sequence by rear wheel cylinders, anti-lock system components and calipers.
See BLEEDING SEQUENCE table.
BLEEDING SEQUENCE
Application
(1)
Sequence
All Models RR, LR, RF, LF
(1)
Bleed master cylinder first, then specified wheel.
DIAGNOSIS
NOTE: Always disconnect negative battery cable before checking resistance on RABS
II system. Inaccurate measurements will result if battery remains connected.
Before condemning circuit, check connectors for dirty or corroded terminals.
CAUTION: When battery is disconnected, vehicle computer and memory systems
may lose memory data. Driveability problems may exist until computer
article in the GENERAL INFORMATION section before disconnecting
battery.
COMPONENT LOCATIONS
COMPONENT LOCATIONS
Component Location
ABS Control Module Behind Center Of Dashboard
Diode/Resistor Element
Windshield Washer Reservoir
RABS Diagnostic Test Connector
Or Behind Kick Panel
Speed Sensor
Differential Housing
RABS Valve Assembly Under Master Cylinder
Sensor Test Connector
Cylinder
SYSTEM PRELIMINARY CHECK
Vehicle Setup
Before retrieving trouble codes, ensure vehicle is on a level area. Shift 4WD models into 2-wheel drive. On all
models, transmission should be in Park (A/T) or Neutral (M/T). Turn ignition off. Set parking brake. Turn
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Red BRAKE Warning Light Check
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
Turn ignition switch to START position. Red BRAKE warning light should be on. If light is not on, go to
TEST A under PRELIMINARY TESTS. Allow ignition switch to return to RUN position. Red BRAKE
warning light should turn off. If light does not turn off, check parking brake switch. Repair/replace switch as
necessary. If light remains on and parking brake switch is functioning properly, go to TEST B under
PRELIMINARY TESTS.
Yellow ABS Warning Light Check
1. Follow procedure for RED BRAKE WARNING LIGHT CHECK. When ignition switch returns to RUN
from START position, Yellow light should stay on for 2 seconds and then turn off. If Yellow light turns
back on but does not flash, check for stored trouble codes. See RETRIEVING TROUBLE CODES. If
Yellow light does not turn on, go to TEST C under PRELIMINARY TESTS.
2. Depress brake pedal 1-2 seconds, then release. Yellow light should not flash. If Yellow light begins to
flash, go to TEST D under PRELIMINARY TESTS.
PRELIMINARY TESTS
Test A - Red BRAKE Warning Light Does Not Self-Check
1. Turn ignition on. Engage parking brake. If Red BRAKE warning light comes on, release parking brake
and go to next step. If Red BRAKE warning light does not come on, repair open in circuit or fuse to Red
BRAKE warning light. After repairs, perform SYSTEM PRELIMINARY CHECK.
2. Disconnect brake fluid warning switch harness connector. Using a jumper wire, jumper brake fluid level
warning switch terminal No. 3 (Dark Green/Yellow wire) to ground. If Red BRAKE warning light comes
on, go to next step. If Red BRAKE warning light does not come on, repair circuit between switch and
warning light or circuit to diode/resistor element. See WIRING DIAGRAM. After repairs, perform
SYSTEM PRELIMINARY CHECK.
3. Jumper brake fluid level switch harness connector terminals No. 2 (Tan/Light Green wire) and No. 3
(Dark Green/Yellow wire). See WIRING DIAGRAM. If Red BRAKE warning light comes on, replace
brake fluid level warning switch. If Red BRAKE warning light does not come on, check for open in
Tan/Light Green wire circuit. If circuit is okay, replace ignition switch. After repairs, perform SYSTEM
PRELIMINARY CHECK.
Test B - Red BRAKE Warning Light Stays On When Ignition Is In RUN Position
1. Ensure parking brake is disengaged. Turn ignition switch on. If both Red BRAKE and Yellow ABS
warning light stays on after bulb-check, retrieve codes. See RETRIEVING TROUBLE CODES and
diagnose affected code(s). If both warning lights turn off after bulb-check, go to next step.
2. Disconnect parking brake switch. If Red BRAKE warning light comes on, repair short to ground in
Purple/White wire or Light Green/Red wire circuits. See WIRING DIAGRAM. After repairs, perform
SYSTEM PRELIMINARY CHECK. If Red BRAKE warning light did not come on, replace parking
brake switch. After replacing switch, perform SYSTEM PRELIMINARY CHECK.
Test C - Yellow ABS Warning Light Does Not Self-Check
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Observe if Yellow ABS light is flashing a DTC (short and long pulses). If DTC is being flashed, diagnose
. If voltage is greater than 10 volts, go to step 3). If voltage is not greater than
. If resistance is not steady and greater than 5 ohms, repair
go to next step. If voltage is less than 10 volts, repair open in Light Green wire. See
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
1. Check ABS warning light fuse. If fuse is okay, go to next step. If fuse is blown, replace fuse and check
for short to ground in circuit No. 640 (Red/Yellow wire). See WIRING DIAGRAM. After repairs,
perform SYSTEM PRELIMINARY CHECK.
NOTE: Always disconnect battery cable to starter relay when checking resistance
in ABS system.
2. Disconnect negative battery cable. Disconnect ABS control module harness connector. Check resistance
between ground and ABS control module harness connector terminal No. 4 (Light Green/Yellow wire).
See Fig. 1. If resistance is less than 5 ohms, reconnect battery cable and then go to next step. If resistance
is not less than 5 ohms, repair Light Green/Yellow wire circuit. After repairs, perform SYSTEM
PRELIMINARY CHECK.
3. Check voltage between ground and ABS control module harness connector terminal No. 7 (Dark Green
wire). If voltage is not greater than 10 volts, go to next step. If voltage is greater than 10 volts, replace
control module. After replacing control module, perform SYSTEM PRELIMINARY CHECK.
4. Disconnect instrument cluster harness connector. Check resistance on Dark Green wire between
instrument cluster harness connector terminal and ABS control module harness connector terminal. See
WIRING DIAGRAM. If resistance is less than 5 ohms, diagnose instrument cluster. See
INSTRUMENT PANEL article in the ACCESSORIES & EQUIPMENT section. If resistance is not less
than 5 ohms, repair Dark Green wire circuit. After repairs, perform SYSTEM PRELIMINARY
CHECK.
Test D - Yellow ABS Warning Light Self-Checks Okay, But Automatically Begins Flashing
1.
affected DTC(s). If DTC is not being flashed, go to next step.
2. Turn ignition off. Disconnect ABS control module harness connector. Turn ignition on. Check voltage
between ground and ABS control module harness connector terminal No. 12 (Black/Orange wire), while
wiggling harness. See Fig. 1
10 volts, repair Black/Orange wire circuit. After repairs, perform SYSTEM PRELIMINARY CHECK.
3. On all models, turn ignition off. Disconnect negative battery cable. Check resistance between ground and
ABS control module harness connector terminal No. 4 (Light Green/Yellow wire), while wiggling
harness.
4. If resistance is 5 ohms or less and steady, replace control module harness connector. After repairs,
perform SYSTEM PRELIMINARY CHECK
Light Green/Yellow wire. After repairs, perform SYSTEM PRELIMINARY CHECK.
Test E - Yellow ABS Warning Light Self-Checks Okay, But No DTCs Retrieved When Diagnostics Are Started
1. Turn ignition on. Depress brake pedal and observe stoplights. If stoplights come on, go to next step. If
stoplights do not come on, replace stoplight bulbs or brake switch. After repairs, perform SYSTEM
PRELIMINARY CHECK.
2. Turn ignition off. Disconnect ABS control module. Depress brake pedal. Check voltage between ground
and ABS control module harness connector terminal No. 11. See Fig. 1. If voltage is 10 volts or greater,
WIRING
Page 99
DIAGRAM
.
No. 1 (Light Blue Pink wire) and No. 9 (Light Blue/Pink wire). If voltage is 10 volts or greater, go to next
operating properly. If Yellow light does not flash, go to
under PRELIMINARY TESTS.
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
3. Turn ignition on. Check voltage between ground and ABS control module harness connector terminals
step. If voltage is less than 10 volts, repair Light Blue/Pink wire circuit. After repairs, perform SYSTEM
PRELIMINARY CHECK.
4. Observe Yellow ABS warning light. If Yellow ABS warning light is on, repair short to ground in Dark
Green wire between ABS light and control module. See WIRING DIAGRAM. After repairs, perform
SYSTEM PRELIMINARY CHECK. If Yellow ABS warning light is not on, go to next step.
5. Turn ignition off. Check resistance between ground and ABS control module harness connector terminal
No. 12 (Black/Orange wire). If resistance is 5 ohms or less, replace ABS control module. After replacing
module, perform SYSTEM PRELIMINARY CHECK. If resistance is greater than 5 ohms, repair
Black/Orange wire between control module and fuse block. See WIRING DIAGRAM. After repairs,
perform SYSTEM PRELIMINARY CHECK.
RETRIEVING TROUBLE CODES
NOTE: When retrieving trouble codes, connect only the Black/Orange wire to ground.
Connecting mating connector wire to ground will blow fuse.
1. Turn ignition on, with engine off. Locate Black RABS test connector. See COMPONENT
LOCATIONS. Connector has 2 mating halves. One has a Black/Orange wire; other has a Red wire.
Disconnect connector. Connect jumper wire to connector terminal with Black/Orange wire. Ground other
end of jumper wire for at least one second. When ground circuit is completed and then broken, Yellow
ABS warning light will flash trouble code.
2. Code will repeat until ignition is turned off. Trouble code consists of a number of short flashes followed
by one long flash. Count each flash, short and long, to determine code number. For example: short, short,
long, is Code 3. Perform appropriate code test after retrieving code. A Code 16 indicates system is
TEST E
Page 100
Turn ignition off. Disconnect and reconnect diagnostic connector (Black/Orange wire) and its mating half
less, go to next step. If resistance is not 5 ohms or less, repair open in Pink/Light Green wire circuit. After
1997 Ford Pickup F150
1997 ANTI-LOCK BRAKE SYSTEM Anti-Lock - RABS II - "F" Series Pickup
Fig. 1: Identifying ABS Control Module Connector Terminals
Courtesy of FORD MOTOR CO.
CLEARING CODES
To clear codes stored in Keep Alive Memory (KAM), turn ignition off, while ABS test connector halves
Black/Orange wire and Red wire are separated. Reconnect ABS test connector to provide power to KAM.
TROUBLE CODE DIAGNOSIS
NOTE: After disconnecting battery, drive vehicle 10 miles in order to allow Powertrain
Control Module to relearn its adaptive strategy.
CODE 2
1.
(Red). Turn ignition on. If Yellow ABS warning light comes on, go to next step. If Yellow ABS warning
light does not come on, DTC is an intermittent fault, go to INTERMITTENT DIAGNOSIS.
2. Turn ignition off. Disconnect RABS valve and ABS control module harness connector. Check resistance
between ABS control module harness connector terminal No. 13 (Pink/Light Green wire) and RABS
valve harness connector terminal No. 4 (Pink/Light Green wire). See Fig. 1. If resistance is 5 ohms or
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