Page 1
TABLE OF CONTENTS
1.0 INTRODUCTION .........................................................1
1.1 SYSTEM COVERAGE ...............................................1
1.2 SIX-STEP TROUBLESHOOTING PROCEDURE ..........................1
2.0 IDENTIFICATION OF SYSTEM .............................................1
3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION ......................1
3.1 TEVES ABS SYSTEM DESCRIPTION ..................................1
3.1.2 TRACTION CONTROL SYSTEM (TCS) DESCRIPTION ....................2
3.1.3 PEDAL FEEL/VEHICLES CHARACTERISTICS ....................2
3.1.4 SYSTEM COMPONENTS......................................3
3.1.5 ABS AND RED BRAKE WARNING INDICATOR....................3
3.1.4 CONTROLLER ANTILOCK BRAKE (CAB) ........................3
3.1.6 HYDRAULIC CONTROL UNIT ..................................4
3.1.7 SENSORS ..................................................4
3.2 ABS DIAGNOSTIC TROUBLE CODES ..................................4
3.2.1 SYSTEM INITIALIZATION......................................4
3.2.2 DIAGNOSTIC MODE .........................................5
3.2.3 INTERMITTENT DIAGNOSTIC TROUBLE CODES .................5
3.3 USING THE DRBIIIT .................................................5
3.4 DRBIIIT ERROR MESSAGES .........................................5
3.4.1 DRBIIIT DOES NOT POWER UP (BLANK SCREEN)................5
3.4.2 DISPLAY IS NOT VISIBLE .....................................5
4.0 DISCLAIMERS, SAFETY, WARNINGS .......................................6
4.1 DISCLAIMERS......................................................6
4.2 SAFETY...........................................................6
4.2.1 TECHNICIAN SAFETY INFORMATION...........................6
4.3 WARNING .........................................................7
4.4 DIAGNOSIS........................................................7
5.0 REQUIRED TOOLS AND EQUIPMENT ......................................7
6.0 GLOSSARY OF TERMS...................................................8
7.0 DIAGNOSTIC INFORMATION AND PROCEDURES ............................9
BRAKES (CAB)
CAB POWER FEED CIRCUIT .............................................10
CLUSTER FAULT .......................................................13
CONTROLLER FAILURE .................................................14
INCORRECT TONE WHEEL ..............................................16
LEFT FRONT SENSOR CIRCUIT FAILURE ..................................17
LEFT FRONT SENSOR SIGNAL FAILURE...................................22
LEFT REAR SENSOR CIRCUIT FAILURE ...................................25
LEFT REAR SENSOR SIGNAL FAILURE ....................................30
4.2.2 VEHICLE PREPARATION FOR TESTING.........................6
4.2.3 SERVICING SUB-ASSEMBLIES ................................6
4.2.4 DRBIIIT SAFETY INFORMATION................................6
4.3.1 VEHICLE DAMAGE WARNINGS................................7
4.3.2 ROAD TESTING A COMPLAINT VEHICLE........................7
i
Page 2
TABLE OF CONTENTS - Continued
PCI BUS COMMUNICATION ..............................................33
PUMP MOTOR NOT WORKING PROPERLY.................................35
RIGHT FRONT SENSOR CIRCUIT FAILURE.................................38
RIGHT FRONT SENSOR SIGNAL FAILURE..................................43
RIGHT REAR SENSOR CIRCUIT FAILURE ..................................46
RIGHT REAR SENSOR SIGNAL FAILURE...................................51
SYSTEM OVERVOLTAGE ................................................54
SYSTEM UNDERVOLTAGE ...............................................56
*TRACTION CONTROL SWITCH...........................................58
COMMUNICATION
*NO RESPONSE FROM CAB .............................................61
VERIFICATION TESTS
VERIFICATION TESTS...................................................63
8.0 COMPONENT LOCATIONS...............................................65
8.1 CONTROLLER ANTILOCK BRAKE ....................................65
8.2 DATA LINK CONNECTOR ...........................................65
8.3 FUSES...........................................................65
8.4 HYDRAULIC CONTROL UNIT ........................................66
8.5 PUMP MOTOR ....................................................66
8.6 TONE WHEELS....................................................66
8.7 Wheel Speed Sensors...............................................67
8.8 Wheel Speed Sensor Connectors .....................................68
8.9 TRACTION CONTROL SWITCH ......................................68
8.10 BRAKE LAMP SWITCH.................................................................69
9.0 CONNECTOR PINOUTS .................................................71
BRAKE LAMP SWITCH - GRAY 6 WAY .....................................71
CONTROLLER ANTI-LOCK BRAKE - 25 WAY ................................71
DATA LINK CONNECTOR - BLACK 16 WAY .................................72
FUSES................................................................74
CIRCUIT BREAKERS ....................................................74
HEADLAMP RELAY (LHD) ................................................74
HEADLAMP RELAY (RHD)................................................75
LEFT FRONT WHEEL SPEED SENSOR - BLACK 2 WAY ......................75
LEFT FRONT WHEEL SPEED SENSOR (SENSOR SIDE) ......................75
LEFT REAR WHEEL SPEED SENSOR - BLACK 2 WAY........................75
LEFT REAR WHEEL SPEED SENSOR (SENSOR SIDE) .......................76
FUSES................................................................78
A/C COMPRESSOR CLUTCH RELAY.......................................78
AUTOMATIC SHUT DOWN RELAY.........................................78
ENGINE STARTER MOTOR RELAY ........................................78
FUEL PUMP RELAY .....................................................79
HIGH SPEED RADIATOR FAN RELAY ......................................79
HORN RELAY ..........................................................79
LOW SPEED RADIATOR FAN RELAY ......................................79
TRANSMISSION CONTROL RELAY ........................................79
PUMP MOTOR CONNECTOR (CONNECTOR SIDE) ..........................80
RIGHT FRONT WHEEL SPEED SENSOR - BLACK 2 WAY .....................80
RIGHT FRONT WHEEL SPEED SENSOR (SENSOR SIDE).....................80
ii
Page 3
TABLE OF CONTENTS - Continued
RIGHT REAR WHEEL SPEED SENSOR - BLACK 2 WAY ......................81
RIGHT REAR WHEEL SPEED SENSOR (SENSOR SIDE) ......................81
TRACTION CONTROL SWITCH - WHITE 4 WAY .............................81
TRACTION CONTROL SWITCH (SWITCH SIDE) .............................82
10.0 SCHEMATIC DIAGRAMS.................................................83
iii
Page 4
NOTES
iv
Page 5
GENERAL INFORMATION
1.0 INTRODUCTION
The procedures contained in this manual include
all the specifications, instructions, and graphics
needed to diagnose Mark 20 Antilock Braking System (ABS) problems. The diagnostics in this manual are based on the failure condition or symptom
being present at time of diagnosis.
Please follow the recommendations below when
choosing your diagnostic path.
1. First make sure the DRBIIIt is communicating
with the CAB. If the DRBIIIt displays a “No
Response” condition, you must diagnose that
first.
2. Read DTC’s (diagnostic trouble codes) with the
DRBIIIt.
3. If no DTC’s are present, identify the customer
complaint.
4. Once the DTC or customer complaint is identi-
fied, locate the matching test in the Table of
Contents and begin to diagnose the symptom.
All component location views are in Section 8.0.
All connector pinouts are in Section 9.0. All schematics are in Section 10.0.
An * placed before the symptom description indicated a customer complaint.
When repairs are required, refer to the appropriate service manual for the proper removal and
repair procedure.
Diagnostic procedures change every year. New
diagnostic systems may be added; carryover systems may be enhanced. READ THIS MANUAL
BEFORE TRYING TO DIAGNOSE A VEHICLE
CODE. It is recommended that you review the
entire manual to become familiar with all new and
changed diagnostic procedures.
After using this book, if you have any comments
or recommendations, please fill out the form at the
back of the book and mail it back to us.
1.1 SYSTEM COVERAGE
This diagnostic manual covers the Teves Mark 20
Antilock Braking System (ABS) with traction control found on the 2001 PT Cruiser.
1.2 SIX-STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the antilock brake system is done in
six basic steps:
• verification of complaint
• verification of any related symptoms
• symptom analysis
• problem isolation
• repair of isolated problem
• verification of proper operation
2.0 IDENTIFICATION OF SYSTEM
Vehicles equipped with the Teves Mark 20 antilock brake system with traction control can be
identified by the presence of the hydraulic control
unit located with the controller antilock brake
(CAB) under the hood near the air cleaner housing,
or by observing the ABS lamp illumination during
the bulb check.
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
3.1 TEVES ABS SYSTEM DESCRIPTION
This section covers the physical and operational
descriptions, and the diagnostic service procedures
for the Teves Mark 20 Antilock Brake System with
traction control. It is the only antilock brake system
(ABS) available on this vehicle.
The purpose of the antilock brake system is to
prevent wheel lockup under braking conditions on
virtually any type of road surface. Antilock braking
is desirable because a vehicle that is stopped without locking the wheels retains directional stability
and some steering capability. This allows the driver
to retain greater control of the vehicle during braking.
All vehicles are equipped with ABS and use
Electronic Brake Distribution (EBD) to balance
front-to-rear braking when the brakes are applied
in the partial braking range.
A Controller Antilock Brake (CAB) module is
used to monitor wheel speeds and to modulate
(control) hydraulic pressure in each brake channel
when ABS or traction control are actuated.
During a non-ABS stop, the system functions as a
standard diagonally split configuration. The primary supplies brake fluid pressure to the right
front and left rear brakes, and the secondary supplies the right rear and left front brakes. A conventional proportioning valve is not used. This system
uses the existing ABS solenoids to replace and
perform the same functions that the proportioning
valves do. The CAB has a special software program
that monitors the wheel speeds and when certain
critera are met the software will enable the solenoids to perform the same brake fluid management
control as the proportioning valves.
During an ABS stop, the system still uses the
diagonally hydraulic split; however, the brake sys-
1
Page 6
GENERAL INFORMATION
tem pressure is further split into four control channels. During and ABS operation, all wheels are
controlled independently and are on four separate
control channels.
During an antilock stop, “wheel lock-up” does not
necessarily mean that the wheel has locked, it
means only that the wheel is turning slower than
the vehicle speed. This is called “wheel slip” and is
indicated as a percentage. 0% slip means that the
wheel is rolling free and 100% slip means that the
wheel is locked. The antilock system maintains an
average of approximately 20% wheel slip.
It is important to remember that the antilock
brake system does not shorten the vehicle stopping
distance under all driving conditions, but provides
improved control of the vehicle while stopping.
Vehicle stopping distance is still dependent on vehicle speed, weight, tires, road surface, and other
factors.
3.1.2 TRACTION CONTROL SYSTEM (TCS)
DESCRIPTION
The Traction Control System is available on this
vehicle only withABS. The main purpose of traction
control is to reduce wheel slip and maintain traction
at the driven wheels when road surfaces are wet or
snow covered. The traction control system reduces
wheel slip by braking the wheel that is losing
traction. The system is designed to operate at
speeds below 56 km/h (35 mph).
The control module monitors wheel speed. If
during acceleration the module detects front (drive)
wheel slip and the brakes are not applied, the
control module will enter traction control mode.
Traction control works in the following order when
drive wheel slip is detected.
1. Close the (normally open) isolation valves.
2. Start pump/motor and supply volume/pressure
to front hydraulic circuits (pump runs continuously during traction control).
3. Open and close build and decay valves to main-
tain minimum wheel slip and maximum traction.
The cycling of the build and decay valves works
similar to ABS except that they work to control
wheel spin by applying brakes. ABS function is to
control wheel skid by releasing brakes.
Two pressure relief valves allow pressure/volume
to return to the reservoir when not consumed by the
build/decay cycles. These are required because the
pump supplies more volume than the system requires.
If at any time the brakes are applied during a
traction control cycle, the brake switch will trigger
the control module to switch off the traction control.
The traction control system will be enabled at
each ignition cycle. It may be turned off by depressing the traction control switch. The traction control
system function lamp will illuminate ‘‘TRAC OFF’’
immediately upon depressing the traction control
switch button. The lamp above the odometer will
display ‘‘TRAC’’ during a traction control cycle. If
the controller calculates that the brake temperatures are high, the traction control system will
become inoperative until a time-out period has
elapsed. When in this thermal protection mode, the
traction control ‘‘TRAC OFF’’ lamp will illuminate;
however, a fault will not be registered.
3.1.3 PEDAL FEEL/VEHICLES
CHARACTERISTICS
There are several pedal feel/vehicle characteristics that are considered normal for antilock braking
that may require further explanation.
When stopping conditions activate the antilock
brakes, the driver may feel some vibrations/
pulsations in the brake pedal and may hear the
electric solenoid valves clicking and the pump motor running. The vibrations/pulsations are caused
by the isolating, building and decaying of brake
fluid pressure within the brake lines. The ABS
system prevents complete wheel lock-up, but some
wheel slip is required for the best braking performance. This slip may result in some tire chirping,
depending on the road surface. The chirping sound
should not be interpreted as total wheel lock-up,
which leaves black tire marks on dry pavement;
antilock braking may leave some light marks.
At the end of an ABS stop, the ABS may function
all the way down to near 0 km/h (0 mph). There may
be a slight brake pedal drop anytime the ABS is
deactivated.
In case of braking on a bumpy surface, the ABS
system may detect wheel locking tendencies due to
wheel hop and cycleABS. In the scenario the brake
pedal may pulsate with a perceived loss of declaration. ABS braking may also be activated at times
while on dry pavement with sand, gravel, or other
loose debris on the road.
It should be noted that the pulsating pedal feel
characteristic will not illuminate the brake warning
lamps or set a trouble code that is stored in the
Controller Antilock Brake (CAB). When investigating a hard pedal feel, inspect the sensor and tone
wheel teeth for chips/broken teeth, damaged sensor
pole tips, excessive runout of the tone wheel, or
excessive gap.
2
Page 7
GENERAL INFORMATION
3.1.4 SYSTEM COMPONENTS
ANTILOCK BRAKE SYSTEM
• Integrated Controller Unit (ICU)
mounting bracket
controller antilock brake (CAB)
hydraulic control unit (HCU)pump/motor as-
sembly:
1 motor
2 pumps
valve block assembly: 10 valves/solenoids (4
• vacuum booster
• master cylinder (w/center valves and fluid reser-
voir)
• 4 wheel speed sensor/tone wheel assemblies
• ABS warning indicator (cluster)
• Trac off indicator (cluster)
• fuses and wiring harness (w/trac on/off switch)
3.1.5 ABS AND RED BRAKE WARNING
The amber ABS warning indicator is located in
the instrument cluster. It is used to inform the
driver that the antilock function has been turned off
due to a system malfunction. The CAB controls the
lamp indirectly. The CAB monitors its own functions. If the CAB determines that theABS indicator
should be on, the CAB sends a message via the PCI
BUS to the instrument cluster and the cluster turns
on the indicator. The instrument cluster sends a
message over the PCI BUS, if the CAB does not
respond the instrument cluster will illuminate the
ABS indicator.
The red brake warning indicator is located in the
instrument cluster. It can be activated by application of the parking brake, a leak in the front or rear
wheel brake hydraulic circuit which causes the
master cylinder reservoir to be low on fluid, or by
turning the ignition switch to the start position.
The red brake warning indicator can also be turned
on if the CAB indicates an EBD failure.
INDICATOR
inlet valves, 4 outlet
valves, 2 traction control valves.).
2 hydraulic shuttle
valves
2 accumulators
3.1.4 CONTROLLER ANTILOCK BRAKE (CAB)
The antilock brake controller (CAB) is a
microprocessor-based device that monitors wheel
speeds and controls the antilock functions.
The primary functions of the CAB are:
• monitor wheel speeds
• detect wheel locking tendencies
• detect wheel slip
• control fluid pressure modulation to the brakes
during antilock stop and traction control operation
• monitor the system for proper operation
• provide communication to the DRBIIIt while in
diagnostic mode
• store diagnostic information in non-volatile
memory
The CAB continuously monitors the speed of each
wheel. When a wheel locking tendency is detected,
the CAB will command the appropriate valve to
modulate brake fluid pressure in its hydraulic unit.
Brake pedal position is maintained during an antilock stop by being a closed system with the use of
3 accumulators. The CAB continues to control pressure in individual hydraulic circuits until a wheel
locking tendency is no longer present. The CAB
turns on the pump/motor during an antilock stop.
The antilock brake system is constantly monitored by the CAB for the proper operation. If the
CAB detects a system malfunction, it can disable
the antilock system and turn on the antilock warning lamp. If the antilock function is disabled, the
system will revert to standard base brake system
operation.
The CAB inputs include the following:
• four wheel speed sensors
• brake lamp switch
• ignition switch
• battery voltage
• diagnostic communication (PCI BUS)
• traction control switch
The CAB outputs include the following:
• ten valve/solenoid drivers
• pump/motor actuation
• ABS warning indicator actuation (PCI BUS)
• red brake warning indicator actuation (PCI BUS)
• Trac off lamp (PCI BUS)
• Trac lamp (PCI BUS)
• diagnostic communication (PCI BUS)
3
Page 8
GENERAL INFORMATION
3.1.6 HYDRAULIC CONTROL UNIT
The hydraulic control unit (HCU) contains the
valve block assembly, two accumulators, and the
pump/motor assembly.
Valve Block Assembly: The valve block assembly contains a total of 12 valves; 10 solenoid valves
with four inlet valves and four outlet valves, and
two traction control valves and two hydraulic shuttle valves. The inlet valves are spring-loaded in the
open position and the outlet valves are spring
loaded in the closed position. During an antilock
stop, these valves are cycled to maintain the proper
slip ratio for each channel. If a wheel locks, the inlet
valve is closed to prevent any further pressure
increase. Then the outlet valve is opened to release
the pressure to the accumulators until the wheel is
no longer slipping. Once the wheel is no longer
slipping, the outlet valve is closed and the inlet
valve is opened to reapply pressure. If the wheel is
decelerating within its predetermined limits (proper slip ratio), both valves will close to hold the
pressure constant. The valves are also cycled during
a traction control event.
Pump/Motor Assembly: The pump/motor assembly provides the extra amount of fluid needed
during antilock braking. The pump is supplied fluid
that is released to the accumulators when the outlet
valve is opened during an antilock stop. The pump
is also used to drain the accumulator circuits after
the antilock stop is complete. The pump is operated
by an integral electric motor. This DC-type motor is
controlled by the CAB. The CAB turns on the motor
when an antilock stop is detected. The pump con-
tinues to run during the antilock stop and is turned
off approximately 3-5 seconds after the stop is
complete. The pump mechanism consists of two
opposing pistons operated by an eccentric cam. One
piston supplies the primary hydraulic circuit. The
opposing piston supplies the secondary hydraulic
circuit. In operation, one piston draws fluid from
the accumulators. The opposing piston pumps fluid
to the valve body solenoids. The CAB monitors the
pump/motor operation internally.
Accumulators: The 3.0mm accumulators provide temporary fluid storage during an antilock
stop and are drained by the pump/motor.
3.1.7 SENSORS
Wheel Speed Sensors and Tone Wheels: One
Wheel Speed Sensor (WSS) is located at each wheel
and sends a small digital signal to the control
module (CAB). The CAB sends 12 volts down to the
sensor. The sensor has an internal magneto resistance bridge that alters the voltage and amperage
of the signal circuit. This voltage and amperage is
changed by magnetic induction when a toothed
sensor ring (tone wheel) passes by a stationary
magnetic sensor (wheel speed sensor). The CAB
measures the voltage and amperage of the digital
signals for each wheel.
The front wheel sensor is attached to a boss in the
steering knuckle. The tone wheel is an integral part
of the front axle shaft. The rear speed sensor is
mounted in the caliper adapter plate and the rear
tone wheel is an integral part of the rear rotor hub.
• The wheel speed sensor air gap is NOT adjust-
able.
• Wheel speed sensors cannot be checked for resis-
tance to determine if they are ok.
Correct antilock system operation is dependent
on wheel speed signals from the wheel speed sensors. The vehicle’s wheels and tires should all be the
same size and type to generate accurate signals. In
addition, the tires should be inflated to the recommended pressures for optimum system operation.
Variations in wheel and tire size or significant
variations in inflation pressure can produce inaccurate wheel speed signals; however the system will
continue to function when using the mini-spare.
3.2 ABS DIAGNOSTIC TROUBLE CODES
The Teves Mark 20Antilock Brake System (ABS)
module may report any of the following diagnostic
trouble codes:
• CAB Power Feed Circuit
• Cluster Fault
• Controller Failure
• Incorrect Tone Wheel
• Left Front Sensor Circuit Failure
• Left Front Sensor Signal Failure
• Left Rear Sensor Circuit Failure
• Left Rear Sensor Signal Failure
• PCI Bus Communication
• Pump Motor Circuit Not Working Properly
• Right Front Sensor Circuit Failure
• Right Front Sensor Signal Failure
• Right Rear Sensor Circuit Failure
• Right Rear Sensor Signal Failure
• System Overvoltage
• System Undervoltage
Diagnostic trouble codes are retained in memory
until erased using the DRBIIIt, or automatically
erased after 255 key cycles or 3500 miles.
3.2.1 SYSTEM INITIALIZATION
System initialization starts when the key is
turned to ‘‘run’’. At this point, the CAB performs a
complete self-check of all electrical components in
the antilock brake systems. The ABS, TRAC OFF,
4
Page 9
GENERAL INFORMATION
TRAC and brake warning lamps will illuminate for
4 seconds with ignition on.
AT20 km/h (12 mph) a dynamic test is performed.
This will momentarily run the pump/motor. If during the dynamic test, the driver has his/her foot on
the brake pedal, he/she may feel the test through
brake pedal pulsations. This is a normal condition.
If any component exhibits a diagnostic trouble
code during system initialization or dynamic check,
the CAB will illuminate the ABS and TRAC off
warning lamps.
3.2.2 DIAGNOSTIC MODE
On a Mark 20 system to enter a diagnostic mode,
vehicle speed must be below 10 km/h (6 mph) and
no ABS condition present. If vehicle speed is not
below 10 km/h (6 mph), a ‘‘no response’’ message
could be displayed by the DRBIIIt. The following
are characteristics of diagnostic mode:
• The amber ABS and red brake warning indicator
will blink rapidly (about 1/2 second on and 1/2
second off). If a hard trouble code is present, such
as CAB Power Feed Circuit diagnostic trouble
code, the indicator will be illuminated without
blinking until the diagnostic trouble condition is
corrected.
• Antilock operation is disabled.
3.2.3 INTERMITTENT DIAGNOSTIC
TROUBLE CODES
If the malfunction is not present while performing a test procedure, the diagnostic procedures will
not locate the problem. In this case, the code can
only suggest an area to inspect. Check for the
following:
• loose or corroded conditions
• damaged components (sensors, tone wheels)
• damaged wiring
• excessive axle shaft runout
• hydraulic system leaks
• regular brake system problems, non-ABS related
If not obvious problems are found, erase diagnostic trouble codes and with the key on, wiggle the
wire harness and connectors. Recheck for codes
periodically as you work through the system. This
procedure may uncover a difficult to locate malfunction.
3.4 DRBIIIT ERROR MESSAGES
Under normal operation, the DRBIIIt will dis-
play one of only two error messages:
– User-Requested WARM Boot or User-
Requested COLD Boot
If the DRBIIIt should display any other error
message, record the entire display and call the
STAR Center for information and assistance. This
is a sample of such an error message display:
ver: 2.14
date: 26 Jul93
file: key_itf.cc
date: Jul 26 1993
line: 548
err. 0x1
User-Requested COLD Boot
Press MORE to switch between this display
and the application screen.
Press F4 when done noting information.
3.4.1 DRBIIIT DOES NOT POWER UP
(BLANK SCREEN)
If the LED’s do not light orno sound is emitted at
start up, check for loose cable connections or a bad
cable. Check the vehicle battery voltage (data link
16-way connector cavity 16).A minimum of 11 volts
is required to adequately power the DRBIIIt. Also
check for a good ground at the DLC.
If all connections are proper between the
DRBIIIt and the vehicle or other devices, and the
vehicle battery is fully charged, an inoperative
DRBIIIt may be the result of faulty cable or vehicle
wiring.
3.4.2 DISPLAY IS NOT VISIBLE
Low temperatures will affect the visibility of the
display. Adjust the contrast to compensate for this
condition.
3.3 USING THE DRBIIIT
Refer to the DRBIIIt user’sguide for instructions
and assistance with reading diagnostic trouble
codes, erasing diagnostic trouble codes and other
DRBIIIt functions.
5
Page 10
GENERAL INFORMATION
4.0 DISCLAIMERS, SAFETY,
WARNINGS
4.1 DISCLAIMERS
All information, illustrations, and specifications
contained in this manual are based on the latest
information available at the time of publication.
The right is reserved to make changes at any time
without notice.
4.2 SAFETY
4.2.1 TECHNICIAN SAFETY INFORMATION
WARNING: ENGINES PRODUCE CARBON
MONOXIDE THAT IS ODORLESS, CAUSES
SLOWER REACTION TIME, AND CAN LEAD
TO SERIOUS INJURY. WHEN THE ENGINE IS
OPERATING, KEEP SERVICE AREAS WELL
VENTILATED OR ATTACH THE VEHICLE
EXHAUST SYSTEM TO THE SHOP EXHAUST
REMOVAL SYSTEM.
Set the parking brake and block the wheels before
testing or repairing the vehicle. It is especially
important to block the wheels on the vehicle; the
parking brake does not hold the front drive wheels.
When servicing a vehicle, always wear eye protection, and remove any metal jewelry such as
watchbands or bracelets that might make an inadvertent electrical contact.
When diagnosing an antilock brake or speed
proportional steering system problem, it is important to follow approved procedures where applicable. These procedures can be found in the service
manual. Following these procedures is very important to the safety of individuals diagnostic tests.
4.2.2 VEHICLE PREPARATION FOR
TESTING
Make sure the vehicle being tested has a fully
charged battery.If it does not, false diagnostic codes
or error messages may occur.
4.2.3 SERVICING SUB-ASSEMBLIES
Some components of the antilock brake or speed
proportional steering system are intended to be
serviced in assembly only. Attempting to remove or
repair certain system sub-components may result
in personal injury and/or improper system operation. Only those components with approved repair
and installation procedures in the service manual
should be serviced.
4.2.4 DRBIIIT SAFETY INFORMATION
WARNING: EXCEEDING THE LIMITS OF THE
DRBIIIT MULTIMETER IS DANGEROUS. IT
CAN EXPOSE YOU TO SERIOUS OR
POSSIBLY FATAL INJURY. CAREFULLY
READ AND UNDERSTAND THE CAUTIONS
AND THE SPECIFICATIONS LIMITS.
• Follow the vehicle manufacturer’s service speci-
fications at all times.
• Do not use the DRBIIIt if it has been damaged.
• Do not use the test leads if insulation is damaged
or if metal is exposed.
• To avoid electrical shock, do not touch the test
leads, tips, or the circuit being tested.
• Choose the proper range and function for the
measurement. Do not try voltage or current measurements that may exceed the rated capacity.
• Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts AC
0 - 500 volts DC
Ohms (resistance)* 0 - 1.12 megohms
Frequency Measured
Frequency Generated
Temperature -58 - 1100°F
* Ohms cannot be measured if voltage is
present. Ohm can be measured only in a
non-powered circuit.
• Voltage between any terminal and ground must
not exceed 500v DC or 500v peak AC.
• Use caution when measuring voltage above 25v
DC or 25v AC.
• Use the low current shunt to measure circuits up
to 10A. Use the high current clamp to measure
circuits exceeding 10A.
• When testing for the presence of voltage or cur-
rent, make sure the meter is functioning correctly. Take a reading of a known voltage or
current before accepting a zero reading.
• When measuring current, connect the meter in
series with test lead.
• When using the meter function, keep the
DRBIIIt away from spark plug or coil wires to
avoid measuring error from outside interference.
0-10kHz
-50 - 600°C
6
Page 11
GENERAL INFORMATION
4.3 WARNING
4.3.1 VEHICLE DAMAGE WARNINGS
Before disconnecting any control module, make
sure the ignition is ‘‘off’’. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation, this will damage it and eventually cause
it to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second code could be set, making diagnosis of the
original problem more difficult.
4.3.2 ROAD TESTING A COMPLAINT
VEHICLE
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
CAUTION: BEFORE ROAD TESTING A
VEHICLE, BE SURE THAT ALL
COMPONENTS ARE REASSEMBLED.
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRBIIIT SCREEN WHILE IN
MOTION. DO NOT HANG THE DRBIIIT FROM
THE REAR VIEW MIRROR OR OPERATE IT
YOURSELF. HAVE AN ASSISTANT
AVAILABLE TO OPERATE THE DRBIIIT.
4.4 DIAGNOSIS
1. Your diagnostic test procedure must begin with a
thorough visual inspection of the ABS system for
damaged components or disconnected connectors. The brake lamps must be operational, and
if they are not, repair them prior to continuing.
2. Connect the DRBIIIt to the data link connector,
located under the dash to the left of the steering
column. If the DRBIIIt does not power up, check
the power and ground supplies to the connector.
3. Select ‘‘Antilock Brakes’’. Turn the ignition on. If
the DRBIIIt displays ‘‘No Response’’, perform
the proper test.
4. Read and record all ABS diagnostic trouble
codes. If the ‘‘CAB Power Feed Circuit’’ diagnostic trouble code is present, it must be repaired
prior to addressing any other DTC’s. If any
additional codes are present, proceed to the
appropriate test.
5. If there are no diagnostic trouble codes present,
select ‘‘Inputs/Outputs’’ and read the brake
switch input as you press and release the brake
pedal. If the display does not match the state of
the pedal, perform the proper test. Read the
‘‘Traction Control Switch’’ status, the switch
should read ‘‘CLOSED’’. If the status is not
correct, perform the proper test. If a problem
with the amber ‘‘ABS’’ warning indicator exists,
refer to the proper test.
6. If no other problems are found, it will be necessary to road test the vehicle. THE DRBIIIt
MUST NOT BE CONNECTED TO THE
DATA LINK CONNECTOR WHEN ROAD
TESTING FOR PROPER ANTILOCK OPERATION. THE SYSTEM IS DISABLED
WHILE IN DIAGNOSTIC MODE. Perform
several antilock stops from above 50 Km/h (30
mph) and then repeat steps 2, 3, and 4. If any
diagnostic trouble codes are present, proceed to
the appropriate test.
7. The following conditions should be considered
‘‘NORMAL’’ operation, and no repairs should be
attempted to correct them.
– Brake pedal feedback during an ABS stop
(clicking, vibrating)
– Clicking, groaning or buzzing at 20 Km/h (12
mph) (drive off self test)
– Groaning noise during an ABS stop
– Slight brake pedal drop and pop noise when
ignition is initially turned on
– Brake pedal ratcheting down at the end of an
ABS stop.
8. If the complaint is ABS ‘‘cycling’’ at the end of a
stop at low speeds, it may be caused by a
marginal wheel speed sensor signal. The sensor
air gap, tone wheel condition, and/or brakes
hanging up are possible causes of this condition.
9. After a road test and no problems were found,
refer to any TechnicalService Bulletins that may
apply.
5.0 REQUIRED TOOLS AND
EQUIPMENT
DRBIIIt (diagnostic read-out box)
jumper wires
ohmmeter
voltmeter
test light
7
Page 12
GENERAL INFORMATION
6.0 GLOSSARY OF TERMS
ABS antilock brake system
AC alternating current
CAB controller antilock brake
DC direct current
DLC data link connector
DRB diagnostic read-out box
EBD electronic brake distribution
EMI electro magnetic interference
HCU hydraulic control unit
HZ Hertz
LF left front
LR left rear
PCI Programmable Communication In-
terference
PCM Powertrain Control Module
PDC power distribution center
P/M pump motor
RF right front
RR right rear
RFI radio frequency interference
SOL solenoid
WSS wheel speed sensor
8
Page 13
DIAGNOSTIC INFORMATION AND
7.0
PROCEDURES
9
Page 14
BRAKES (CAB)
Symptom:
CAB POWER FEED CIRCUIT
When Monitored and Set Condition:
CAB POWER FEED CIRCUIT
When Monitored: Ignition on. The CAB monitors the Fused B+ circuit at all times for
proper system voltage.
Set Condition: If the Fused B+ voltage is missing when the CAB detects that an internal
main driver is not 9on9, the Diagnostic Trouble Code (DTC) is set.
POSSIBLE CAUSES
INTERMITTENT DTC
FUSE BLOWN - FUSED B(+) CIRCUIT
FUSED B(+) CIRCUIT OPEN
FUSED B(+) CIRCUIT SHORTED TO GROUND
FUSED B(+) CIRCUIT INTERMITTENTLY SHORTED TO GROUND
CAB - FUSED B(+) CIRCUIT OPEN
CAB - FUSED B(+) CIRCUIT SHORTED TO GROUND
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase DTC’s.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTC’s.
Is the CAB Power Feed Circuit DTC present right now?
Yes → Go To 2
No → Go To 10
2 Turn the ignition off.
Remove and Inspect ABS SOL Fuse in the PDC.
Is the Fuse blown?
Yes → Go To 3
No → Go To 8
All
All
3 Turn the ignition off.
Visually inspect the Fused B(+) Circuit in the wiring harness from the PDC to the
CAB. Look for any sign of an intermittent short to ground.
Is the wiring harness OK?
Yes → Go To 4
No → Repair the Fused B(+) Circuit Shorted to Ground.
Perform ABS VERIFICATION TEST.
10
All
Page 15
BRAKES (CAB)
CAB POWER FEED CIRCUIT — Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the ABS SOL Fuse from the PDC.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Using a test light connected to 12 volts, probe the Fused B(+) Circuit.
Is the test light on?
Yes → Repair the Fused B(+) Circuit Shorted to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 5
All
5 Turn the ignition off.
Disconnect the ABS SOL Fuse from the PDC.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Fused Ignition Switch Output circuit between the Fuse
and the CAB connector.
Is the resistance below 5 ohms?
Yes → Go To 6
No → Repair Fused B(+) Circuit Open.
6 Turn the ignition off.
Disconnect the ABS SOL Fuse from the PDC.
Using a test light connected to 12 volts, probe the Fused B(+) Circuit.
Is the test light on?
Yes → Replace the CAB.
No → Go To 7
7 Turn the ignition off.
If there are no potential causes remaining, replace the Fuse.
View repair options.
Repair
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Replace the Fuse.
Perform ABS VERIFICATION TEST.
8 Turn the ignition off.
Disconnect the ABS SOL Fuse from the PDC.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Fused Ignition Switch Output circuit between the Fuse
and the CAB connector.
Is the resistance below 5 ohms?
Yes → Go To 9
No → Repair Fused B(+) Circuit Open.
Perform ABS VERIFICATION TEST.
9 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
Replace the CAB.
Perform ABS VERIFICATION TEST.
11
All
All
Page 16
BRAKES (CAB)
CAB POWER FEED CIRCUIT — Continued
TEST ACTION APPLICABILITY
10 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Repair as necessary.
Perform ABS VERIFICATION TEST.
No → Test Complete.
All
12
Page 17
Symptom:
CLUSTER FAULT
When Monitored and Set Condition:
CLUSTER FAULT
When Monitored: Ignition on, every time a message is sent from the instrument cluster.
Set Condition: This DTC will be set when the message from the instrument cluster, via
PCI Bus, informs the CAB that it can not turn on the ABS Warning Indicator or the Red
Brake Warning Indicator.
POSSIBLE CAUSES
INTERMITTENT DTC
CLUSTER FAULT DTC CONDITION PRESENT
BRAKES (CAB)
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, try to communicate with the Mechanical Instrument Cluster
(MIC), not the CAB module.
Does the DRBIIIt display 9Bus +/- Signal Open?
Yes → Refer to symptom *BUS +/- SIGNALS OPEN FROM INSTRU-
2 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
No → Go To 2
Yes → Repair as necessary.
No → Test Complete.
All
MENT CLUSTER in the COMMUNICATION category.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
13
Page 18
BRAKES (CAB)
Symptom:
CONTROLLER FAILURE
When Monitored and Set Condition:
CONTROLLER FAILURE
When Monitored: Ignition on. Two microprocessors, internal to the CAB, calculate the
wheel speed independently of each other then compare the results.
Set Condition: If the values that each microprocessor calculate for wheel speed differ by
more than 1.5% for more than 70 milliseconds (MS), the Diagnostic Trouble Code (DTC) is
set.
POSSIBLE CAUSES
GROUND CIRCUIT CONNECTION POOR
GROUND CIRCUIT OPEN
CAB - GROUND CIRCUIT OPEN
GROUND CIRCUIT RADIO FREQUENCY INTERFERENCE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the CAB harness connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between ground and both of the ground circuits.
Is the resistance below 1.0 ohm for both measurements?
Yes → Go To 2
No → Repair the Ground circuit(s) for an open.
2 Turn the ignition on.
With the DRBIIIt, actuate the pump motor.
Measure the voltage drop across the CAB ground circuit connection with the pump
motor running.
Is the voltage above 0.10 volts?
Yes → Repair Ground Circuit Poor Connection.
No → Go To 3
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
14
Page 19
BRAKES (CAB)
CONTROLLER FAILURE — Continued
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Turn the ignition on.
Turn on all accessories.
Measure the voltage of the ground circuit at the CAB.
Measure the voltage of the ground circuit.
Is the voltage below 1.0 volts?
Yes → Go To 4
No → Repair as necessary. Unsplice any accessories connected to the
CAB ground circuit. Reroute and shield any high voltage cables
away from the CAB ground circuit.
Perform ABS VERIFICATION TEST.
All
4 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
15
Page 20
BRAKES (CAB)
Symptom:
INCORRECT TONE WHEEL
When Monitored and Set Condition:
INCORRECT TONE WHEEL
When Monitored: Every 7 milliseconds (ms).
Set Condition: Requires 2 minutes to detect that all wheels are above 40 km/h (24 mph).
POSSIBLE CAUSES
INCORRECT TONE WHEEL
INCORRECT TIRES
TEST ACTION APPLICABILITY
1 Inspect the tire sizes on the vehicle.
Is a smaller than production tire, or two mini spares installed on both front wheels?
All
Yes → Replace the incorrect tire(s) size with production size tire(s).
No → Go To 2
2 Count the number of tone wheel teeth on both of the front driveshafts.
Does one or both of the front driveshaft teeth have 40 teeth?
Yes → Replace the front dirveshaft(s) with the incorrect number of tone
No → Test Complete.
Perform ABS VERIFICATION TEST.
All
wheel teeth. Note: Driveshafts for 1997 and earlier vehicles can
not be used on this vehicle, because the number of tone wheel
teeth are different between the Bendix and Teves systems.
Perform ABS VERIFICATION TEST.
16
Page 21
Symptom:
LEFT FRONT SENSOR CIRCUIT FAILURE
When Monitored and Set Condition:
LEFT FRONT SENSOR CIRCUIT FAILURE
When Monitored: Ignition on. The CAB monitors the wheel speed circuit every 7
milliseconds (ms).
Set Condition: If the CAB detects an open or shorted wheel speed sensor circuit, the
Diagnostic Trouble Code (DTC) will set.
POSSIBLE CAUSES
LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT OPEN
LEFT FRONT WHEEL SPEED SENSOR SIGNAL
BRAKES (CAB)
LEFT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
INTERMITTENT CIRCUIT DTC
LEFT FRONT WHEEL SPEED SENSOR DEFECTIVE - SHORTED TO GROUND
LEFT FRONT WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
CAB - LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY OPEN
CAB - LEFT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
CAB - LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY SHORTED TO GROUND
CAB - LEFT FRONT WHEEL SPEED SIGNAL CIRCUIT SHORTED TO GROUND
CAB - UNABLE TO READ LEFT FRONT WHEEL SPEED SENSOR SIGNAL
LEFT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
LEFT FRONT WHEEL SPEED SENSOR CIRCUITS SHORTED TOGETHER
LEFT FRONT WHEEL SPEED SENSOR SIGNAL SHORTED TO B(+)
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
With the DRBIIIt erase DTC’s.
Turn ignition off.
Turn ignition on.
With the DRBIIIt, read DTC’s.
Is the Left Front Wheel Speed Sensor Circuit Failure DTC present right now?
All
Yes → Go To 2
No → Go To 17
17
Page 22
BRAKES (CAB)
LEFT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
2 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage across the Left Front Wheel Speed Sensor 12 VoltSupply circuit
and the Left Front Wheel Speed Sensor Signal circuit in the Left Front Wheel Speed
Sensor connector.
Is the voltage above 10 volts?
Yes → Go To 3
No → Go To 7
All
3 Turn ignition off.
Inspect the Left Front Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 4
4 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between both of the Left Front Wheel Speed Sensor
Terminals and ground.
Is the resistance below 15,000 ohms?
Yes → Replace the Left Front Wheel Speed Sensor.
No → Go To 5
5 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Left Front Wheel Speed Sensor Signal circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Go To 6
No → Replace the Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
6 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
Replace the CAB.
Perform ABS VERIFICATION TEST.
18
All
Page 23
BRAKES (CAB)
LEFT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
7 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Left Front Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Front Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 5 ohms?
Yes → Go To 8
No → Repairthe Left Front Wheel Speed Sensor 12 Volt Supply Circuit
Open.
Perform ABS VERIFICATION TEST.
All
8 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Left Front Wheel Speed Sensor Signal Circuit
and ground.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Front Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 5 ohms?
Yes → Go To 9
No → Repair the Left Front Wheel Speed Sensor Signal Circuit Open.
9 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Front Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Left Front Wheel Speed Sensor 12 VoltSupply Circuit
All
Perform ABS VERIFICATION TEST.
All
Shorted to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 10
19
Page 24
BRAKES (CAB)
LEFT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
10 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Front Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Left Front Wheel Speed Sensor Signal Circuit Shorted
to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 11
All
11 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Left Front Wheel Speed Sensor Circuits.
Is the resistance below 200 ohms?
Yes → Repair the Left Front Wheel Speed Sensor Circuits Shorted
No → Go To 12
12 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Left Front Wheel Speed Sensor Signal Circuit.
Is the voltage above 1 volt?
Yes → Repair Left Front Wheel Speed Sensor Signal Cricuit Shorted to
No → Go To 13
13 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Left Front Wheel Speed Sensor 12 Volt Supply Circuit.
Is the voltage above 10 volts?
All
Together and Replace the Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
Voltage and Replace Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
Yes → Go To 14
No → Replace the CAB.
Perform ABS VERIFICATION TEST.
20
Page 25
BRAKES (CAB)
LEFT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
14 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Front Wheel Speed Sensor
Signal Circuit.
Is the test light on?
Yes → Go To 15
No → Replace the CAB.
Perform ABS VERIFICATION TEST.
All
15 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Front Wheel Speed Sensor 12
Volt Supply Circuit.
Is the test light on?
Yes → Replace the CAB.
No → Go To 16
16 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Front Wheel Speed Sensor
Signal Circuit.
Is the test light on?
17 Turn ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Replace the CAB.
No → Test Complete.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Repair as necessary.
Perform ABS VERIFICATION TEST.
No → Test Complete.
21
Page 26
BRAKES (CAB)
Symptom:
LEFT FRONT SENSOR SIGNAL FAILURE
When Monitored and Set Condition:
LEFT FRONT SENSOR SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed continuity is checked every 7 milliseconds. Wheel speed phase length
supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
TONE WHEEL DEFECTIVE
LEFT FRONT WHEEL SPEED SENSOR SIGNAL
INTERMITTENT SIGNAL DTC
LEFT FRONT WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
LEFT FRONT WHEEL BEARING OUT OF SPECIFICATION
LEFT FRONT WHEEL SPEED SENSOR FUNCTIONAL TEST
LEFT FRONT WHEEL SPEED SENSOR AIR GAP OUT OF SPECIFICATION
CAB - UNABLE TO READ LEFT FRONT WHEEL SPEED SENSOR SIGNAL
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
Are the Left Front Sensor Signal Failure and Left Front Sensor Circuit Failure
DTC’s present now?
Yes → Refer to symptom LEFT FRONT SENSOR CIRCUIT FAILURE
No → Go To 2
2 Turn ignition on.
Have an assistant drive the vehicle while you monitor the Left Front Wheel Speed
Sensor Signal, using the DRBIIIt.
Slowly accelerate as straight as possible from a stop to 24 Km/h (15 Mph).
With the DRBIIIt, monitor all wheel speed sensor signals.
Did the Left Front Wheel Speed Sensor Signal show 0 Km/h (0 Mph)?
All
in the BRAKES (CAB) category.
All
Yes → Go To 3
No → Go To 10
22
Page 27
BRAKES (CAB)
LEFT FRONT SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
3 Turn ignition off.
Inspect the Tone Wheel for damaged or missing teeth.
Note: The Tone Wheel Teeth should be perfectly square, not bent or nicked.
Is the Tone Wheel OK?
Yes → Go To 4
No → Replace the Tone Wheel.
Perform ABS VERIFICATION TEST.
All
4 Turn ignition off.
Inspect the Left Front Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 5
5 Turn ignition off.
Inspect the wheel bearings for excessive runout or clearance.
Note: Refer to the appropriate service information, if necessary, for procedures or specifications.
Is the bearing clearance OK ?
Yes → Go To 6
No → Repair as necessary.
6 Turn ignition off.
Using a Feeler Gauge, measure the Sensor Air Gap.
Note: The Air Gap should be checked in at least four places on the Tone
Wheel.
Is the Air Gap between 0.30 mm - 1.50 mm (0.0129 - 0.0599)?
Yes → Go To 7
No → Repair as necessary.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
7 Turn ignition off.
Disconnect the Left Front Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Connect a single jumper wire from the harness side of Left Front Wheel Speed Sensor
12 Volt Supply circuit into the Left Front Wheel Speed Sensor connector mating
terminal.
Using a voltmeter in Direct Current (DC) mode, probe the Left Front Wheel Speed
Sensor Signal Circuit at Left Front Wheel Speed Sensor connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 8
No → Replace the Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
23
All
Page 28
BRAKES (CAB)
LEFT FRONT SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
8 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Left Front Wheel Speed Sensor Signal circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 9
No → Replace the Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
9 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
10 Turn ignition off.
Visually Inspect Wheel Speed Sensor.
Visually Inspect Tone Wheel.
Visually Inspect Wiring Harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?
Yes → Repair as necessary.
No → Test Complete.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
24
Page 29
Symptom:
LEFT REAR SENSOR CIRCUIT FAILURE
When Monitored and Set Condition:
LEFT REAR SENSOR CIRCUIT FAILURE
When Monitored: Ignition on. The CAB monitors the wheel speed circuit every 7
milliseconds (ms).
Set Condition: If the CAB detects an open or shorted wheel speed sensor circuit, the
Diagnostic Trouble Code (DTC) will set.
POSSIBLE CAUSES
LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT OPEN
LEFT REAR WHEEL SPEED SENSOR SIGNAL
BRAKES (CAB)
LEFT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
LEFT REAR WHEEL SPEED SENSOR 12 SUPPLY CIRCUIT SHORTED TO GROUND
LEFT REAR WHEEL SPEED SENSOR DEFECTIVE - SHORTED TO GROUND
LEFT REAR WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
CAB - LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY OPEN
CAB - LEFT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
CAB - LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY SHORTED TO GROUND
CAB - LEFT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
CAB - UNABLE TO READ LEFT REAR WHEEL SPEED SENSOR SIGNAL
LEFT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
LEFT REAR WHEEL SPEED SENSOR CIRCUITS SHORTED TOGETHER
LEFT REAR WHEEL SPEED SENSOR SIGNAL SHORTED TO B(+)
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
With the DRBIIIt, erase DTC’s.
Turn ignition off.
Turn ignition on.
With the DRBIIIt, read DTC’s.
Is the Left Rear Wheel Speed Sensor Circuit Failure DTC present right now?
All
Yes → Go To 2
No → Go To 17
25
Page 30
BRAKES (CAB)
LEFT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
2 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage across the Left Rear Wheel Speed Sensor 12 Volt Supply circuit
and the Left Rear Wheel Speed Sensor Signal Circuit in the Left Rear Wheel Speed
Sensor connector.
Is the voltage above 10 volts?
Yes → Go To 3
No → Go To 7
All
3 Turn ignition off.
Inspect the Left Rear Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 4
4 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between either one of the Left Rear Wheel Speed Sensor
terminals and ground.
Is the resistance below 15,000 ohms?
Yes → Replace the Left Rear Wheel Speed Sensor.
No → Go To 5
5 Turn ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Left Rear Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Go To 6
No → Replace the Left Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
6 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
Replace the CAB.
Perform ABS VERIFICATION TEST.
26
All
Page 31
BRAKES (CAB)
LEFT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
7 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Left Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Measure the resistance between the Left Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 5 ohms?
Yes → Go To 8
No → Repair the Left Rear Wheel Speed Sensor 12 Volt Supply Circuit
Open.
Perform ABS VERIFICATION TEST.
All
8 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Left Rear Wheel Speed Sensor Signal Circuit and
ground.
Measure the resistance between the Left Rear Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 5 ohms?
Yes → Go To 9
No → Repair the Left Rear Wheel Speed Sensor Signal Circuit Open.
9 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Left Rear Wheel Speed Sensor 12 Volt Supply Circuit
All
Perform ABS VERIFICATION TEST.
All
Shorted to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 10
10 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Left Rear Wheel Speed Sensor Circuits.
Is the resistance below 200 ohms?
Yes → Repair the Left Rear Wheel Speed Sensor Circuits shorted
together and Replace the Left Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
No → Go To 11
27
All
Page 32
BRAKES (CAB)
LEFT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
11 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Left Rear Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Left Rear Wheel Speed Sensor Signal Circuit Shorted
to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 12
All
12 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Left Rear Wheel Speed Sensor Signal Circuit.
Is the voltage above 1 volt?
Yes → Repair Left Rear Wheel Speed Sensor Signal Circuit Shorted to
No → Go To 13
13 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Left Rear Wheel Speed Sensor 12 Volt Supply Circuit.
Is the test light on?
Yes → Go To 14
No → Replace the CAB.
14 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Rear Wheel Speed Sensor
Signal Circuit.
Is the test light on?
All
Voltage and Replace Left Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Go To 15
No → Replace the CAB.
Perform ABS VERIFICATION TEST.
28
Page 33
BRAKES (CAB)
LEFT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
15 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Rear Wheel Speed Sensor 12
Volt Supply Circuit.
Is the test light on?
Yes → Replace the CAB.
Perform ABS VERIFICATION TEST.
No → Go To 16
All
16 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Left Rear Wheel Speed Sensor
Signal Circuit.
Is the test light on?
Yes → Replace the CAB.
No → Test Complete.
17 Turn ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Test Complete.
No → Test Complete.
All
Perform ABS VERIFICATION TEST.
All
29
Page 34
BRAKES (CAB)
Symptom:
LEFT REAR SENSOR SIGNAL FAILURE
When Monitored and Set Condition:
LEFT REAR SENSOR SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed continuity is checked every 7 milliseconds. Wheel speed phase length
supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
TONE WHEEL DEFECTIVE
LEFT REAR WHEEL SPEED SENSOR SIGNAL
INTERMITTENT SIGNAL DTC
LEFT REAR WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
LEFT REAR WHEEL BEARING OUT OF SPECIFICATION
LEFT REAR WHEEL SPEED SENSOR FUNCTIONAL TEST
LEFT REAR WHEEL SPEED SENSOR AIR GAP OUT OF SPECIFICATION
CAB - UNABLE TO READ LEFT REAR WHEEL SPEED SENSOR SIGNAL
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
Are Left Rear Sensor Signal Failure and Left Rear Sensor Circuit Failure DTC’s
present right now?
Yes → Refer to symptom LEFT REAR SENSOR CIRCUIT FAILURE in
No → Go To 2
2 Turn ignition on.
Have an assistant drive the vehicle while you monitor the Left Rear Wheel Speed
Sensor Signal, using the DRBIIIt.
Slowly accelerate as straight as possible from a stop to 24 Km/h (15 Mph).
With the DRBIIIt, monitor all wheel speed sensor signals.
Did the Left Rear Wheel Speed Sensor Signal show 0 Km/h (0 Mph)?
All
the BRAKES (CAB) category.
All
Yes → Go To 3
No → Go To 10
30
Page 35
BRAKES (CAB)
LEFT REAR SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
3 Turn ignition off.
Inspect the Tone Wheel for damaged or missing teeth.
Note: The Tone Wheel Teeth should be perfectly square, not bent or nicked.
Is the Tone Wheel OK?
Yes → Go To 4
No → Replace the Tone Wheel.
Perform ABS VERIFICATION TEST.
All
4 Turn ignition off.
Inspect the Left Rear Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 5
5 Turn ignition off.
Inspect the Wheel Bearings for excessive runout or clearance.
Note: Refer to the appropriate service information, if necessary, for procedures or specifications.
Is the Bearing Clearance OK?
Yes → Go To 6
No → Repair as necessary.
6 Turn ignition off.
Using a Feeler Gauge measure the Wheel Speed Sensor Air Gap.
Note: The Air Gap should be checked in at least Four places on the Tone
Wheel.
Is the Air Gap between 0.50 mm - 1.25 mm (0.0199 - 0.0499)?
Yes → Go To 7
No → Repair as necessary.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
7 Turn ignition off.
Disconnect the Left Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Connect a single jumper wire from the harness side of Left Rear Wheel Speed Sensor
12 Volt Supply Circuit into the Left Rear Wheel Speed Sensor connector mating
terminal.
Using a voltmeter in Direct Current (DC) mode, measure the Left Rear Wheel Speed
Sensor Signal Circuit at Left Rear Wheel Speed Sensor conector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 8
No → Replace the Left Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
31
All
Page 36
BRAKES (CAB)
LEFT REAR SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
8 Turn ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Left Rear Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 9
No → Replace the Left Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
9 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
10 Turn ignition off.
Visually Inspect Wheel Speed Sensor.
Visually Inspect Tone Wheel.
Visually Inspect Wiring Harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?
Yes → Repair as necessary.
No → Test Complete.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
32
Page 37
Symptom:
PCI BUS COMMUNICATION
When Monitored and Set Condition:
PCI BUS COMMUNICATION
When Monitored: Ignition on, every 7 milliseconds (ms).
Set Condition: This DTC will be set when the CAB does not recieve a message from the
instrument cluster for 10 seconds.
POSSIBLE CAUSES
INTERMITTENT DTC
PCI BUS OPEN TO CAB
CAB - PCI CIRCUIT OPEN
BRAKES (CAB)
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase DTC’s.
Turn ignition off.
Turn the ignition on.
Wait 20 seconds.
Is the PCI Bus Communication DTC present?
Yes → Go To 2
2 Turn the ignition on.
With the DRBIIIt, read Mechanical Instrument Cluster (MIC) Diagnostic Trouble
Codes (DTC’s).
Does the MIC have the 9ABS Message Not Received by MIC9 DTC set?
3 Turn the ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the PCI Bus Circuit between the CAB connector and the
Data Link Connector (DLC) .
Is the resistance below 5 ohms?
No → Go To 6
Yes → Refer to symptom ABS MESSAGES NOT RECEIVED BY MIC in
No → Go To 3
All
All
the INSTRUMENT CLUSTER category.
All
Yes → Go To 4
No → Repair the PCI Bus Circuit Open.
Perform ABS VERIFICATION TEST.
33
Page 38
BRAKES (CAB)
PCI BUS COMMUNICATION — Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary
Turn the ignition on.
Using the DRBIIIt Lab Scope, measure the voltage of the PCI BUS circuit.
Is the voltage above 0.4 volts?
Yes → Go To 5
No → Go To 5
All
5 If there are no potential causes remaining, replace the CAB.
Replace the CAB.
Repair
6 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Repair as necessary.
No → Test Complete.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
34
Page 39
Symptom:
PUMP MOTOR NOT WORKING PROPERLY
When Monitored and Set Condition:
PUMP MOTOR NOT WORKING PROPERLY
When Monitored: Ignition on. The CAB commands the pump on at 25 km/h (15 mph) to
check its operation, if the brake switch is not applied. If the driver has their foot on the
brake, the test will run at 40 km/h (25 mph). The CAB monitors pump voltage every 7
milliseconds.
Set Condition: The DTC is stored when the CAB detects: 1) Improper voltage decay after
the pump was turned off. 2) Pump not energized by the CAB, but voltage is present for 3.5
seconds. 3) Pump is turned on by the CAB, but their is insufficient voltage to operate it.
POSSIBLE CAUSES
FUSE BLOWN - PUMP MOTOR CIRCUIT
BRAKES (CAB)
GROUND CIRCUIT POOR CONNECTION
FUSED B(+) CIRCUIT OPEN
CAB - FUSED B(+) CIRCUIT OPEN
ABS PUMP MOTOR DOES NOT ROTATE
CAB - FUSED B(+) CIRCUIT SHORTED TO GROUND
FUSED B(+) CIRCUIT INTERMITTENTLY SHORTED TO GROUND
FUSED B(+) CIRCUIT SHORTED TO GROUND
CAB - PUMP MOTOR RUNNING CONTINUOUSLY
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
Is the CAB Power Feed Circuit DTC present now?
Yes → Refer to symptom CAB POWER FEED CIRCUIT in the BRAKES
No → Go To 2
2 Turn ignition on.
With the DRBIIIt read DTC’s.
With the DRBIIIt erase DTC’s.
Turn ignition off.
Turn ignition on.
With the DRBIIIt actuate the pump motor.
Did the Pump Motor operate as commanded by the DRBIIIt?
All
(CAB) category.
All
No → Go To 3
Yes → Go To 13
35
Page 40
BRAKES (CAB)
PUMP MOTOR NOT WORKING PROPERLY — Continued
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Remove and Inspect the ABS Pump Fuse in the Power Distribution Center.
Is the Fuse blown?
Yes → Go To 4
No → Go To 8
All
4 Turn the ignition off.
Visually inspect the Fused B(+) Circuit in the wiring harness from the Power
Distribution Center (PDC) to the CAB. Look for any sign of an Intermittent Short to
Ground.
Is the wiring harness OK?
Yes → Go To 5
No → Repair the Fused B(+) Circuit shorted to ground.
5 Turn the ignition off.
Disconnect the ABS Pump Fuse from the PDC.
Disconnect the CAB connector.
Check connector - Clean/repair as necessary.
Using a test light connected to 12 volts, probe the Fused B(+) Circuit.
Is the test light on?
Yes → Repair the Fused B(+) Circuit Shorted to Ground.
No → Go To 6
6 Turn the ignition off.
Disconnect the Fuse #8 from the PDC.
Using a test light connected to 12 volts, probe the Fused B(+) circuit.
Monitor the test light.
Is the test light on?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Replace the CAB.
Perform ABS VERIFICATION TEST.
No → Go To 7
7 Turn the ignition off.
If there are no potential causes remaining, replace the fuse.
View repair options
Repair
Replace the ABS Pump Motor Fuse.
Perform ABS VERIFICATION TEST.
8 Turn the ignition on.
With the DRBIIIt, actuate the pump motor.
Measure the voltage drop across the ABS ground circuit connection, with the pump
motor running.
Is the voltage below 0.1 volt?
Yes → Go To 9
No → Repair the poor ground circuit.
Perform ABS VERIFICATION TEST.
36
All
All
Page 41
BRAKES (CAB)
PUMP MOTOR NOT WORKING PROPERLY — Continued
TEST ACTION APPLICABILITY
9 Turn the ignition off.
Disconnect the ABS Pump Fuse from the PDC.
Disconnect the CAB connector.
Check connector - Clean/repair as necessary.
Measure the resistance of the Fused B(+) circuit.
Is the resistance below 5 ohms?
Yes → Go To 10
No → Repair Fused B(+) Circuit Open.
Perform ABS VERIFICATION TEST.
All
10 Turn the ignition off.
Disconnect Pump Motor Connector.
Connect a 10 gauge jumper wire between the pump motor Fused B(+) circuit and a
known good Fused B(+) circuit capable of providing 40 amps.
Connect a 10 gauge jumper wire between the pump motor ground circuit and a
known good body ground.
Monitor pump motor operation.
Is the pump motor running?
Yes → Go To 11
No → Replace the ABS Pump Motor.
11 Turn the ignition off.
Reconnect all connectors.
Turn the ignition on.
Monitor the pump motor for continuous operation.
Is the pump motor running continuously?
Yes → Replace the CAB.
No → Go To 12
12 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
13 Turn ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Test Complete.
No → Test Complete.
37
All
Page 42
BRAKES (CAB)
Symptom:
RIGHT FRONT SENSOR CIRCUIT FAILURE
When Monitored and Set Condition:
RIGHT FRONT SENSOR CIRCUIT FAILURE
When Monitored: Ignition on. The CAB monitors the wheel speed circuit every 7
milliseconds (ms).
Set Condition: If the CAB detects an open or shorted wheel speed sensor circuit, the
Diagnostic Trouble Code (DTC) will set.
POSSIBLE CAUSES
RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT OPEN
RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
RIGHT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RIGHT FRONT WHEEL SPEED SENSOR DEFECTIVE - SHORTED TO GROUND
RIGHT FRONT WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
CAB - RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY OPEN
CAB - RIGHT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
CAB - RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY SHORTED TO GROUND
CAB - RIGHT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
CAB - UNABLE TO READ RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
RIGHT FRONT WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
RIGHT FRONT WHEEL SPEED SENSOR CIRCUITS SHORTED TOGETHER
RIGHT FRONT WHEEL SPEED SENSOR SIGNAL SHORTED TO B(+)
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt read DTC’s.
With the DRBIIIt, erase DTC’s.
Turn ignition off.
Turn ignition on.
With the DRBIIIt, read DTC’s.
Did the Right Front Wheel Speed Sensor Circuit Failure DTC set again right now?
All
Yes → Go To 2
No → Go To 17
38
Page 43
BRAKES (CAB)
RIGHT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
2 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage across the Right Front Wheel Speed Sensor 12 Volt Supply
circuit and the Right Front Wheel Speed Sensor Signal Circuit in the Right Front
Wheel Speed Sensor connector.
Is the voltage above 10 volts?
Yes → Go To 3
No → Go To 7
All
3 Turn ignition off.
Inspect the Right Front Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 4
4 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between either one of the Right Front Wheel Speed Sensor
terminals and ground.
Is the resistance below 15,000 ohms?
Yes → Replace the Right Front Wheel Speed Sensor.
No → Go To 5
5 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Right Front Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Go To 6
No → Replace the Right Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
6 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
Replace the CAB.
Perform ABS VERIFICATION TEST.
39
All
Page 44
BRAKES (CAB)
RIGHT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
7 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Right Front Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Measure the resistance between the Right Front Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 5 ohms?
Yes → Go To 8
No → Repair the Right Front Wheel Speed Sensor 12 Volt Supply
Circuit Open.
Perform ABS VERIFICATION TEST.
All
8 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Right Front Wheel Speed Sensor Signal Circuit
and ground.
Measure the resistance between the Right Front Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 5 ohms?
Yes → Go To 9
No → Repair the Right Front Wheel Speed Sensor Signal Circuit Open.
9 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Right Front Wheel Speed Sensor 12 Volt Circuit
and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Right Front Wheel Speed Sensor 12 Volt Supply
All
Perform ABS VERIFICATION TEST.
All
Circuit Shorted to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 10
40
Page 45
BRAKES (CAB)
RIGHT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
10 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Right Front Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Right Front Wheel Speed Sensor Signal Circuit
Shorted to Ground.
Perform ABS VERIFICATION TEST.
No → Go To 11
All
11 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Right Front Wheel Speed Sensor Circuits.
Is the resistance below 200 ohms?
Yes → Repair the Right Front Wheel Speed Sensor Circuits Shorted
No → Go To 12
12 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Right Front Wheel Speed Sensor Signal circuit.
Is the voltage above 1 volt?
Yes → Repair Right Front Wheel Speed Sensor Signal Cricuit Shorted to
No → Go To 13
13 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Right Front Wheel Speed Sensor 12 Volt Supply Circuit.
Is the voltage above 10 volts?
All
Together and Replace the Right Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
Voltage and Replace Right Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
Yes → Go To 14
No → Replace the CAB.
Perform ABS VERIFICATION TEST.
41
Page 46
BRAKES (CAB)
RIGHT FRONT SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
14 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Front Wheel Speed Sensor
Signal Circuit.
Is the test light on?
Yes → Go To 15
No → Replace the CAB.
Perform ABS VERIFICATION TEST.
All
15 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Front Wheel Speed Sensor
12 Volt Supply Circuit.
Is the test light on?
Yes → Replace the CAB.
No → Go To 16
16 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Front Wheel Speed Sensor
Signal Circuit.
Is the test light on?
17 Turn ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Replace the CAB.
No → Test Complete.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Test Complete.
No → Test Complete.
42
Page 47
Symptom:
RIGHT FRONT SENSOR SIGNAL FAILURE
When Monitored and Set Condition:
RIGHT FRONT SENSOR SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed continuity is checked every 7 milliseconds. Wheel speed phase length
supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
TONE WHEEL DEFECTIVE
BRAKES (CAB)
RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
INTERMITTENT SIGNAL DTC
RIGHT FRONT WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
RIGHT FRONT WHEEL BEARING OUT OF SPECIFICATION
RIGHT FRONT WHEEL SPEED SENSOR FUNCTIONAL TEST
RIGHT FRONT WHEEL SPEED SENSOR AIR GAP OUT OF SPECIFICATION
CAB - UNABLE TO READ RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
Are the Right Front Sensor Signal Failure and Right Front Sensor Circuit Failure
DTC’s present?
Yes → Refer to symptom RIGHT FRONT SENSOR CIRCUIT FAILURE
No → Go To 2
2 Turn ignition on.
Have an assistant drive the vehicle while you monitor the Right Front Wheel Speed
Sensor Signal, using the DRBIIIt.
Slowly accelerate as straight as possible from a stop to 24 Km/h (15 Mph).
With the DRBIIIt, monitor all wheel speed sensor signals.
Did Right Front Wheel Speed Sensor Signal show 0 Km/h (0 Mph)?
All
in the BRAKES (CAB) category.
All
Yes → Go To 3
No → Go To 10
43
Page 48
BRAKES (CAB)
RIGHT FRONT SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
3 Turn ignition off.
Inspect the Tone Wheel for damaged or missing teeth.
Note: The Tone Wheel Teeth should be perfectly square, not bent or nicked.
Is the Tone Wheel OK?
Yes → Go To 4
No → Replace the Tone Wheel.
Perform ABS VERIFICATION TEST.
All
4 Turn ignition off.
Inspect the Right Front Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 5
5 Turn ignition off.
Inspect the wheel bearings for excessive runout or clearance.
Note: Refer to the appropriate service information, if necessary, for procedures or specifications.
Is the bearing clearance OK?
Yes → Go To 6
No → Repair as necessary.
6 Turn ignition off.
Using a Feeler Gauge measure the Wheel Speed Sensor Air Gap.
Note: The Air Gap should be checked in at least four places on the Tone
Wheel.
Is the Air Gap between 0.30 mm - 1.50 mm (0.0129 - 0.0599)?
Yes → Go To 7
No → Repair as necessary.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
7 Turn ignition off.
Disconnect the Right Front Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Connect a single jumper wire from the harness side of Right Front Wheel Speed
Sensor 12 Volt Supply Circuit into the Right Front Wheel Speed Sensor connector
mating terminal.
Using a voltmeter in Direct Current (DC) mode, probe the Right Front Wheel Speed
Sensor signal circuit at Right Front Wheel Speed Sensor connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 8
No → Replace the Right Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
44
All
Page 49
BRAKES (CAB)
RIGHT FRONT SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
8 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Right Front Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 9
No → Replace the Right Front Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
9 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
10 Turn ignition off.
Visually Inspect Wheel Speed Sensor.
Visually Inspect Tone Wheel.
Visually Inspect Wiring Harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?
Yes → Repair as necessary.
No → Test Complete.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
45
Page 50
BRAKES (CAB)
Symptom:
RIGHT REAR SENSOR CIRCUIT FAILURE
When Monitored and Set Condition:
RIGHT REAR SENSOR CIRCUIT FAILURE
When Monitored: Ignition on. The CAB monitors the wheel speed circuit every 7
milliseconds (ms).
Set Condition: If the CAB detects an open or shorted wheel speed sensor circuit, the
Diagnostic Trouble Code (DTC) will set.
POSSIBLE CAUSES
RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT OPEN
RIGHT REAR WHEEL SPEED SENSOR SIGNAL
RIGHT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RIGHT REAR WHEEL SPEED SENSOR DEFECTIVE - SHORTED TO GROUND
RIGHT REAR WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
CAB - RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY CIRCUIT OPEN
CAB - RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY SHORTED TO GROUND
CAB - RIGHT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT OPEN
CAB - RIGHT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
CAB - UNABLE TO READ RIGHT REAR WHEEL SPEED SENSOR SIGNAL
RIGHT REAR WHEEL SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
RIGHT REAR WHEEL SPEED SENSOR CIRCUITS SHORTED TOGETHER
RIGHT REAR WHEEL SPEED SENSOR SIGNAL SHORTED TO B(+)
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
With the DRBIIIt, erase DTC’s.
Turn ignition off.
Turn ignition on.
With the DRBIIIt, read DTC’s.
Did the Right Rear Wheel Speed Sensor Circuit Failure DTC set again?
All
Yes → Go To 2
No → Go To 17
46
Page 51
BRAKES (CAB)
RIGHT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
2 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage across the Right Rear Wheel Speed Sensor 12 VoltSupply circuit
and the Right Rear Wheel Speed Sensor Signal Circuit in the Right Rear Wheel
Speed Sensor connector.
Is the voltage above 10 volts?
Yes → Go To 3
No → Go To 5
All
3 Turn ignition off.
Inspect the Right Rear Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 4
4 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between either one of the Right Rear Wheel Speed Sensor
terminals and ground.
Is the resistance below 15,000 ohms?
Yes → Replace the Right Rear Wheel Speed Sensor.
No → Go To 15
5 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Right Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Measure the resistance between the Right Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 5 ohms?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Go To 6
No → Repairthe Right Rear Wheel Speed Sensor 12 Volt Supply Circuit
Open.
Perform ABS VERIFICATION TEST.
47
Page 52
BRAKES (CAB)
RIGHT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
6 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Connect a jumper wire between the Right Rear Wheel Speed Sensor Signal Circuit
and ground.
Measure the resistance between the Right Rear Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 5 ohms?
Yes → Go To 7
No → Repair the Right Rear Wheel Speed Sensor Signal Circuit Open.
Perform ABS VERIFICATION TEST.
All
7 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Right Rear Wheel Speed Sensor 12 Volt Supply
Circuit and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Right Rear Wheel Speed Sensor 12 VoltSupply Circuit
No → Go To 8
8 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between the Right Rear Wheel Speed Sensor Signal Circuit
and ground.
Is the resistance below 15,000 ohms?
Yes → Repair the Right Rear Wheel Speed Signal Circuit Shorted to
No → Go To 9
All
Shorted to Ground.
Perform ABS VERIFICATION TEST.
All
Ground.
Perform ABS VERIFICATION TEST.
9 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Right Rear Wheel Speed Sensor Circuits.
Is the resistance below 200 ohms?
Yes → Repair the Right Rear Wheel Speed Sensor Circuits Shorted
Together and Replace the Right Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
No → Go To 10
48
All
Page 53
BRAKES (CAB)
RIGHT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
10 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Right Rear Wheel Speed Sensor Signal Circuit.
Is the voltage above 1 volt?
Yes → Repair Right Rear Wheel Speed Sensor Signal Circuit Shorted to
Voltage and Replace Right Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
No → Go To 11
All
11 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Right Rear Wheel Speed Sensor 12 Volt Supply Circuit.
Is the voltage above 10 volts?
Yes → Go To 12
No → Replace the CAB.
12 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Rear Wheel Speed Sensor 12
Volt Supply Circuit.
Is the test light on?
Yes → Replace the CAB.
No → Go To 13
13 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Rear Wheel Speed Sensor
Signal Circuit.
Is the test light on?
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Yes → Replace the CAB.
Perform ABS VERIFICATION TEST.
No → Go To 14
49
Page 54
BRAKES (CAB)
RIGHT REAR SENSOR CIRCUIT FAILURE — Continued
TEST ACTION APPLICABILITY
14 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Using a test light connected to 12 volts, probe the Right Rear Wheel Speed Sensor
Signal Circuit.
Is the test light on?
Yes → Replace the CAB.
Perform ABS VERIFICATION TEST.
No → Go To 15
All
15 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Right Rear Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 16
No → Replace the Right Rear Wheel Speed Sensor.
16 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
17 Turn ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
All
Perform ABS VERIFICATION TEST.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Yes → Test Complete.
No → Test Complete.
50
Page 55
Symptom:
RIGHT REAR SENSOR SIGNAL FAILURE
When Monitored and Set Condition:
RIGHT REAR SENSOR SIGNAL FAILURE
When Monitored: Wheel speed comparison is checked at drive off or every 7 milliseconds
(ms). Wheel speed continuity is checked every 7 milliseconds. Wheel speed phase length
supervision is checked every 7 milliseconds.
Set Condition: If, during an ABS stop, the CAB commands any valve solenoid on for an
extended length of time, and does not see a corresponding wheel speed change, the
Diagnostic Trouble Code (DTC) is set. The DTC can also set if the signal is missing or
erratic.
POSSIBLE CAUSES
TONE WHEEL DEFECTIVE
BRAKES (CAB)
RIGHT REAR WHEEL SPEED SENSOR SIGNAL
INTERMITTENT SIGNAL DTC
RIGHT REAR WHEEL SPEED SENSOR OR CONNECTOR DAMAGED
RIGHT REAR WHEEL BEARING OUT OF SPECIFICATION
RIGHT REAR WHEEL SPEED SENSOR FUNCTIONAL TEST
RIGHT REAR WHEEL SPEED SENSOR AIR GAP OUT OF SPECIFICATION
CAB - UNABLE TO READ RIGHT REAR WHEEL SPEED SENSOR SIGNAL
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIIt, read DTC’s.
Are Right Rear Sensor Signal Failure and Right Rear Sensor Circuit Failure DTC’s
present right now?
Yes → Refer to symptom RIGHT REAR SENSOR CIRCUIT FAILUREin
No → Go To 2
2 Turn ignition on.
Have an assistant drive the vehicle while you monitor the Right Rear Wheel Speed
Sensor Signal, using the DRBIIIt.
Slowly accelerate as straight as possible from a stop to 24 Km/h (15 Mph).
With the DRBIIIt, monitor all wheel speed sensor signals.
Did the Right Rear Wheel Speed Sensor Signal show 0 Km/h (0 Mph)?
All
the BRAKES (CAB) category.
All
Yes → Go To 3
No → Go To 10
51
Page 56
BRAKES (CAB)
RIGHT REAR SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
3 Turn ignition off.
Inspect the Tone Wheel for damaged or missing teeth.
Note: The Tone Wheel Teeth should be perfectly square, not bent or nicked.
Is the Tone Wheel OK?
Yes → Go To 4
No → Replace the Tone Wheel.
Perform ABS VERIFICATION TEST.
All
4 Turn ignition off.
Inspect the Right Rear Wheel Speed Sensor and Connector.
Is the Sensor or Connector Damaged?
Yes → Repair as necessary.
No → Go To 5
5 Turn ignition off.
Inspect the wheel bearings for excessive runout or clearance.
Note: Refer to the appropriate service information, if necessary, for procedures or specifications.
Is the bearing clearance OK?
Yes → Go To 6
No → Repair as necessary.
6 Turn ignition off.
Using a Feeler Gauge, measure the Sensor Air Gap.
Note: The Air Gap should be checked in at least Four places on the Tone
Wheel.
Is the Air Gap between 0.50 mm - 1.25 mm (0.0199 - 0.0499)?
Yes → Go To 7
No → Repair as necessary.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
7 Turn ignition off.
Disconnect the Right Rear Wheel Speed Sensor Connector.
Note: Check connector - Clean/repair as necessary.
Connect a single jumper wire from the harness side of Right Rear Wheel Speed
Sensor 12 Volt Supply circuit into the Right Rear Wheel Speed Sensor connector
mating terminal.
Using a voltmeter in Direct Current (DC) mode, probe the Right Rear Wheel Speed
Sensor Signal circuit at Right Rear Wheel Speed Sensor connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 8
No → Replace the Right Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
52
All
Page 57
BRAKES (CAB)
RIGHT REAR SENSOR SIGNAL FAILURE — Continued
TEST ACTION APPLICABILITY
8 Turn ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Remove harness strain relief to access wires in CAB connector for backprobing.
Using a voltmeter in Direct Current (DC) mode, and special tool 6801, backprobe the
Right Rear Wheel Speed Sensor Signal Circuit at CAB.
Reconnect the CAB connector.
Turn ignition on.
Slowly rotate the wheel while observing voltmeter reading.
Does the voltage change from approximately 1.6 volts to 0.8 volts as the wheel is
rotated?
Yes → Go To 9
No → Replace the Right Rear Wheel Speed Sensor.
Perform ABS VERIFICATION TEST.
All
9 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
10 Visually Inspect Wheel Speed Sensor.
Visually Inspect Tone Wheel.
Visually Inspect Wiring Harness.
Visually inspect brakes for locking up due to lining contamination or overheating.
Inspect all Components for defects which may cause a Signal DTC to set.
Is any Component Damaged?
Yes → Repair as necessary.
No → Test Complete.
All
Replace the CAB.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
53
Page 58
BRAKES (CAB)
Symptom:
SYSTEM OVERVOLTAGE
When Monitored and Set Condition:
SYSTEM OVERVOLTAGE
When Monitored: Ignition on. The CAB monitors the Fused Ignition Switched Output
circuit at all times for proper system voltage.
Set Condition: If the voltage is between 17 and 19 volts for greater than 420 milliseconds
(ms), the Diagnostic Trouble Code (DTC) is set.
POSSIBLE CAUSES
INTERMITTENT DTC
BATTERY OVERCHARGED
FUSED IGNITION SWITCH OUTPUT CIRCUIT OVERVOLTAGE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase DTC’s.
Turn the ignition off.
Turn the ignition on.
Start the engine.
With the DRBIIIt, read DTC’s.
Is the System Overvoltage DTC present?
2 Turn ignition off.
Inspect for battery charger connected to battery.
Is a battery charger connected to the battery?
3 Turn ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Start the engine.
Raise engine RPM’s above 1800.
Measure the voltage of the Fused Ignition Switch Output Circuit.
Is the voltage above 16.5 volts ?
Yes → Go To 2
No → Go To 4
Yes → Charge battery to proper level. Disconnect the battery charger.
No → Go To 3
All
All
Clear DTC’s.
Perform ABS VERIFICATION TEST.
All
Yes → Refer to appropriate service information for charging system
testing and repair.
Perform ABS VERIFICATION TEST.
No → Test Complete.
54
Page 59
BRAKES (CAB)
SYSTEM OVERVOLTAGE — Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Repair as necessary.
Perform ABS VERIFICATION TEST.
No → Test Complete.
All
55
Page 60
BRAKES (CAB)
Symptom:
SYSTEM UNDERVOLTAGE
When Monitored and Set Condition:
SYSTEM UNDERVOLTAGE
When Monitored: Ignition on. The CAB monitors the Fused Ignition Switch Output
circuit voltage every 7 milliseconds for proper system voltage.
Set Condition: If the voltage is below 8 volts, the Diagnostic Trouble Code (DTC) is set.
POSSIBLE CAUSES
INTERMITTENT DTC
FUSED IGNITION SWITCH OUTPUT CIRCUIT HIGH RESISTANCE
FUSED IGNITION SWITCH OUTPUT CIRCUIT UNDERVOLTAGE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase DTC’s.
Turn the ignition off.
Turn the ignition on.
Start the engine.
With the DRBIIIt, read DTC’s.
Is the System Undervoltage DTC present?
Yes → Go To 2
2 Turn ignition on.
With the DRBIIIt, select Sensors.
With the DRBIIIt, read the 9Ignition Voltage9 status and record.
Measure the voltage at the battery and record.
Compare voltage measurements.
Does the DRBIIIt display ignition voltage within one volt of the battery voltage?
No → Go To 4
Yes → Go To 3
No → Repair the Fused Ignition Switch Output Circuit for high resis-
All
All
tance
Perform ABS VERIFICATION TEST.
56
Page 61
BRAKES (CAB)
SYSTEM UNDERVOLTAGE — Continued
TEST ACTION APPLICABILITY
3 Turn ignition off.
Disconnect the CAB connector.
Note: Check connector - Clean/repair as necessary.
Start the engine.
Raise engine RPM’s above 1800.
Measure the voltage of the Fused Ignition Switch Output circuit.
Is the voltage below 13 volts ?
Yes → Refer to appropriate service information for charging system
testing and repair.
Perform ABS VERIFICATION TEST.
No → Test Complete.
All
4 Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?
Yes → Repair as necessary.
No → Test Complete.
All
Perform ABS VERIFICATION TEST.
57
Page 62
BRAKES (CAB)
Symptom:
*TRACTION CONTROL SWITCH
POSSIBLE CAUSES
TRACTION CONTROL SWITCH GROUND CIRCUIT OPEN
TRACTION CONTROL SWITCH SENSE CIRCUIT OPEN
TRACTION CONTROL SWITCH SENSE CIRCUIT SHORTED TO GROUND
TRACTION CONTROL SWITCH STUCK CLOSED
TRACTION CONTROL SWITCH STUCK OPEN
CAB - TRACTION CONTROL SWITCH CIRCUIT SHORTED TO GROUND
CAB - TRACTION CONTROL SWITCH SENSE CIRCUIT OPEN
TEST ACTION APPLICABILITY
1 Turn ignition on.
Depress the Traction Control Switch on dash several times while watching the 9Trac
Off9 Lamp in the Instrument Cluster.
Does Lamp change from 9Trac Off9 to nothing?
All
Yes → Test Complete.
No → Go To 2
2 Turn ignition on.
Depress the Traction Control Switch on dash several times while watching the 9Trac
Off9 Lamp in the Instrument Cluster.
Does the Instrument Cluster display 9Trac Off9 all the time?
3 Turn the ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the Traction Control Switch Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Traction Control Switch Sense circuit and ground.
Is the resistance below 5.0 ohms?
4 Turn ignition off.
Disconnect the Traction Connector Switch Connector.
Note: Check connector - Clean/repair as necessary.
Measure across the Traction Control Switch Sense circuit and Ground circuit, on
Switch.
Measure resistance of the Traction Control Switch.
Is the resistance below 2.0 ohms across switch?
Yes → Go To 3
No → Go To 6
Yes → Repair the Traction Control Switch Sense Circuit Shorted to
No → Go To 4
All
All
Ground.
All
Yes → Replace the Traction Control Switch.
No → Go To 5
58
Page 63
BRAKES (CAB)
*TRACTION CONTROL SWITCH — Continued
TEST ACTION APPLICABILITY
5 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
Replace the CAB.
All
6 Turn ignition off.
Disconnect the Traction Control Switch Connector.
Note: Check connector - Clean/repair as necessary.
Turn ignition on.
Measure the voltage of the Traction Control Switch Sensor Circuit in the vehicle
harness.
Is the voltage above 9 volts.
Yes → Go To 7
No → Go To 9
7 Turn the ignition off.
Disconnect the Traction Control Switch harness connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Ground Circuit in the vehicle harness.
Is the resistance below 5 ohms?
Yes → Go To 8
No → Repair the Ground Circuit Open.
8 Turn ignition off.
Disconnect the Traction Connector Switch Connector.
Note: Check connector - Clean/repair as necessary.
Measure across the Traction Control Switch Sense circuit and Ground circuit, on
Switch.
Depress the Traction Control Switch.
Using an ohmmeter, take measure while depressing the Traction Control Switch.
Is the resistance below 2.0 ohms across switch when the switch is depressed?
All
All
Perform ABS VERIFICATION TEST.
All
Yes → Test Complete.
No → Replace the Traction Control Switch.
9 Turn the ignition off.
Disconnect the CAB Connector.
Note: Check connector - Clean/repair as necessary.
Disconnect the Traction Control Switch Connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance of the Traction Control Switch Sense Circuit.
Is the resistance below 5.0 ohms?
Yes → Go To 10
No → Repair the Traction Control Switch Sense Circuit Open.
59
All
Page 64
BRAKES (CAB)
*TRACTION CONTROL SWITCH — Continued
TEST ACTION APPLICABILITY
10 Turn ignition off.
Disconnect the Traction Connector Switch Connector.
Note: Check connector - Clean/repair as necessary.
Measure across the Traction Control Switch Sense circuit and Ground circuit, on
Switch.
Depress the Traction Control Switch.
Using an ohmmeter, take measure while depressing the Traction Control Switch.
Is the resistance below 2.0 ohms across switch when the switch is depressed?
Yes → Go To 11
No → Replace the Traction Control Switch.
All
11 If there are no potential causes remaining, replace the CAB.
View repair options.
Repair
All
Replace the CAB.
60
Page 65
COMMUNICATION
Symptom:
*NO RESPONSE FROM CAB
POSSIBLE CAUSES
NO RESPONSE FROM CAB
CHECK FUSE #11
GROUND CIRCUIT OPEN
FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
PCI BUS CIRCUIT OPEN
CAB - NO RESPONSE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
As soon as one or more module communicates with the DRBIIIt, answer the
question.
With the DRBIIIt, select PASSIVE RESTRAINTS, then select AIRBAG.
With the DRBIIIt, select MECHANICAL INSTRUMENT CLUSTER.
Were you able to establish communication with any of the modules?
All
Yes → Go To 2
No → Referto symptom PCI BUS COMMUNICATION FAILUREin the
2 Turn the ignition off.
Remove and inspect fuse #11 from the Fuse Block.
Is the Fuse blown?
Yes → Refer to the wiring diagrams located in the service information to
No → Go To 3
3 Turn the ignition off.
Disconnect the CAB harness connector.
Note: Check connector - Clean/repair as necessary.
Measure the resistance between ground and both of the ground circuits.
Is the resistance below 1.0 ohm for both measurements?
Yes → Go To 4
No → Repair the Ground circuit(s) for an open.
COMMUNICATION category.
Perform ABS VERIFICATION TEST.
All
help isolate a possible short to ground condition.
Perform ABS VERIFICATION TEST.
All
Perform ABS VERIFICATION TEST.
61
Page 66
COMMUNICATION
*NO RESPONSE FROM CAB — Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Ensure Fuse #11 is installed.
Disconnect the CAB harness connector.
Note: Check connector - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of the Fused Ignition Switch Output circuit.
Is the voltage above 10.0 volts?
Yes → Go To 5
No → Repair the Fused Ignition Switch Output circuit for an open.
Perform ABS VERIFICATION TEST.
All
5 NOTE: Ensure there is PCI bus communication with other modules. If not,
refer to the PCI Bus Communication Failure symptom and repair as
necessary.
Use Scope input cable CH7058, Cable to Probe adapter CH7062, and the red and
black test probes.
Connect the scope input cable to the channel one connector on the DRB. Attach the
red and black leads and the cable to probe adapter to the scope input cable.
Select DRB Standalone.
Select lab scope.
Select Live.
Select 12 volt square wave.
Press F2 for Scope.
Press F2 and use the down arrow to set voltage range to 20 volts. Press F2 again
when complete.
Disconnect the CAB harness connector.
Connect the Black lead to the chassis ground. Connect the Red lead to the PCI Bus
circuit in the CAB harness connector.
Turn the ignition on.
Observe the voltage display on the DRB Lab Scope.
What is the voltage display on the scope?
Pulse from 0 to approximately 7.5 volts
Steady 0 volts
All
Go To 6
Repair the PCI Bus circuit for an open.
Perform ABS VERIFICATION TEST.
6 If there are no potential causes remaining, view repair. All
Repair
Replace the CAB.
Perform ABS VERIFICATION TEST.
62
Page 67
VERIFICATION TESTS
Verification Tests
ABS VERIFICATION TEST APPLICABILITY
1. Turn ignition off.
2. Connect all previously disconnected components and connectors.
3. Turn the ignition on.
4. With the DRBIIIt, erase DTC’s.
5. With the DRBIIIt, read DTC’s.
6. If any Diagnostic Trouble Codes are present, return to Symptom list and troubleshoot new
or recurring symptom.
7. If there are no DTC’s present after turning ignition on, road test the vehicle for at least 5
minutes. Perform several antilock braking stops.
8. Caution: Ensure braking capability is available before road testing.
9. Again, with the DRBIIIt read DTC’s. If any DTC’s are present, return to Symptom list.
10. If there are no Diagnostic Trouble Codes (DTC’s) present, and the customer’s complaint can
no longer be duplicated, the repair is complete.
All
63
Page 68
NOTES
64
Page 69
8.0 COMPONENT LOCATIONS
8.1 CONTROLLER ANTILOCK BRAKE
LHD
RHD
COMPONENT LOCATIONS
C
O
M
P
O
N
E
N
T
L
O
C
A
T
I
O
N
S
8.2 DATA LINK CONNECTOR
8.3 FUSES
65
Page 70
COMPONENT LOCATIONS
C
O
8.4 HYDRAULIC CONTROL UNIT
M
P
O
N
E
N
T
L
O
C
A
T
I
O
N
S
8.5 PUMP MOTOR
8.6 TONE WHEELS
FRONT
66
Page 71
REAR
8.7 WHEEL SPEED SENSORS
FRONT
COMPONENT LOCATIONS
C
O
M
P
O
N
E
N
T
L
O
C
A
T
I
O
N
S
REAR
67
Page 72
COMPONENT LOCATIONS
C
O
M
8.8 WHEEL SPEED SENSOR CONNECTORS
P
FRONT
O
N
E
N
T
L
O
C
A
T
I
O
N
S
REAR
8.9 TRACTION CONTROL SWITCH
68
Page 73
8.10 BRAKE LAMP SWITCH
COMPONENT LOCATIONS
C
O
M
P
O
N
E
N
T
L
O
C
A
T
I
O
N
S
69
Page 74
C
O
M
P
O
N
E
N
T
O
C
A
T
O
N
S
NOTES
L
I
70
Page 75
9.0 CONNECTOR PINOUTS
CONNECTOR PINOUTS
CAV CIRCUIT FUNCTION
BRAKE LAMP SWITCH - GRAY 6 WAY
1 F32 18PK/DB FUSED B(+)
2 L50 18WT/TN BRAKE LAMP SWITCH OUTPUT
3 V40 20DB/RD SPEED CONTROL BRAKE LAMP SWITCH OUTPUT
4 V32 20YL/RD SPEED CONTROL POWER SUPPLY
5 Z1 20BK GROUND
6 K29 20WT/PK BRAKE LAMP SWITCH SENSE
CONTROLLER ANTI-LOCK BRAKE - 25 WAY
CAV CIRCUIT FUNCTION
1 B8 18RD/DB LEFT FRONT WHEEL SPEED SENSOR SIGNAL
2 B9 18RD LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
3- 4 F12 18DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
5 B3 18LG/DB LEFT REAR WHEEL SPEED SENSOR SIGNAL
6 B4 18LG LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
7- 8 Z1 12BK GROUND
9 A20 12RD/DB FUSED B(+)
10 D25 18VT/YL PCI BUS
11 - 12 - 13 - 14 - 15 B27 18RD/YL TRACTION CONTROL SWITCH SENSE
16 - 17 - 18 L50 18WT/TN BRAKE LAMP SWITCH OUTPUT
19 B6 18WT/DB RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
20 B7 18WT RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
21 - 22 B2 18YL RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
23 B1 18YL/DB RIGHT REAR WHEEL SPEED SENSOR SIGNAL
24 Z1 12BK GROUND
25 A10 12RD/DG FUSED B(+)
C
O
N
N
E
C
T
O
R
P
I
N
O
U
T
S
71
Page 76
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
DATA LINK CONNECTOR - BLACK 16 WAY
1- 2 D25 20VT/YL PCI BUS
3- 4 Z12 20BK/TN GROUND
5 Z11 20BK/WT GROUND
6 D20 20LG SCI RECEIVE
7 D21 20PK SCI TRANSMIT
8- -
9- 10 - 11 - 12 - 13 - 14 D6 20PK/LB SCI RECEIVE (EATX)
15 - 16 A14 18RD/WT FUSED B(+)
P
I
N
O
U
T
S
72
Page 77
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
P
I
N
O
U
T
S
73
Page 78
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
1 F9 20RD/BK FUSED B(+)
2 F33 18PK/RD FUSED B(+)
3 F35 18RD FUSED B(+)
4- 5 F25 18TN/LG FUSED IGNITION SWITCH OUTPUT (RUN)
6 F20 18WT FUSED IGNITION SWITCH OUTPUT (RUN)
7 C1 14DG FUSED IGNITION SWITCH OUTPUT (RUN)
8 F39 18PK/LG HEADLAMP RELAY OUTPUT
9 F15 18DG/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
10 G5 20DB/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
11 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 F18 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 F18 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
13 X12 18RD/WT FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
14 F10 18YL/RD FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
15 F13 16DB FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
16 - 17 - 18 C16 20LB/YL FUSED REAR WINDOW DEFOGGER SWITCH OUTPUT
19 L44 16VT/RD FUSED RIGHT LOW BEAM OUTPUT
20 L43 18VT FUSED LEFT LOW BEAM OUTPUT
20 L43 16VT FUSED LEFT LOW BEAM OUTPUT
CAV CIRCUIT FUNCTION
C.B.
F3 16LB/OR FUSED B(+)
NO. 1
C.B.
F21 14TN FUSED IGNITION SWITCH OUTPUT (RUN)
NO. 2
FUSES
CIRCUIT BREAKERS
P
I
N
O
U
T
S
CAV CIRCUIT FUNCTION
A1 Z1 20BK GROUND
A2 L4 16VT/WT HEADLAMP RELAY OUTPUT
A3 L3 16RD/OR HEADLAMP RELAY CONTROL
A4 F34 18TN/BK HEADLAMP RELAY OUTPUT
A5 F3 16LB/OR FUSED B(+)
HEADLAMP RELAY (LHD)
74
Page 79
CONNECTOR PINOUTS
CAV CIRCUIT FUNCTION
HEADLAMP RELAY (RHD)
B1 Z1 20BK GROUND
B2 L4 16VT/WT HEADLAMP RELAY OUTPUT
B3 L3 16RD/OR HEADLAMP RELAY CONTROL
B4 - B5 F3 16LB/OR FUSED B(+)
LEFT FRONT WHEEL SPEED SENSOR - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 B8 18RD LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 B8 18RD/DB LEFT FRONT WHEEL SPEED SENSOR SIGNAL
LEFT FRONT WHEEL SPEED SENSOR (SENSOR SIDE)
CAV CIRCUIT FUNCTION
1 RD LEFT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 RD/DB LEFT FRONT WHEEL SPEED SENSOR SIGNAL
C
O
N
N
E
C
T
O
R
P
I
N
O
U
T
S
CAV CIRCUIT FUNCTION
1 B4 20LG LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 B3 20LG/DB LEFT REAR WHEEL SPEED SENSOR SIGNAL
LEFT REAR WHEEL SPEED SENSOR - BLACK 2 WAY
75
Page 80
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
LEFT REAR WHEEL SPEED SENSOR (SENSOR SIDE)
1 LG LEFT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 LG/DB LEFT REAR WHEEL SPEED SENSOR SIGNAL
P
I
N
O
U
T
S
76
Page 81
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
P
I
N
O
U
T
S
77
Page 82
CONNECTOR PINOUTS
CAV CIRCUIT FUNCTION
1 A1 14RD FUSED B(+)
2 A10 12RD/DG FUSED B(+)
3 A2 12PK/BK FUSED B(+)
4- 5 A16 12GY FUSED B(+)
6 A120 16RD/LB FUSED B(+)
7 A20 12RD/DB FUSED B(+)
8 A4 12BK/PK FUSED B(+)
9- 10 A3 12RD/WT FUSED B(+)
11 A17 20RD/BK FUSED B(+)
12 F32 18PK/DB FUSED B(+)
13 A14 18RD/WT FUSED B(+)
14 F62 20RD FUSED B(+)
15 A30 16RD/WT FUSED B(+)
16 - 17 - 18 M1 20PK FUSED B(+)
19 A15 18PK/DG FUSED B(+)
C
O
N
N
E
20 F1 16DB/BK FUSED B(+)
21 - 22 F39 18PK/LG FUSED B(+)
23 - 24 - -
C
T
O
R
P
I
N
O
CAV CIRCUIT FUNCTION
D1 C3 20DB/BK A/C COMPRESSOR CLUTCH RELAY OUTPUT
D2 C28 20DB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL
D3 - D4 F18 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
D5 A17 20RD/BK FUSED B(+)
U
T
S
CAV CIRCUIT FUNCTION
E1 A142 18DG/OR AUTOMATIC SHUT DOWN RELAY OUTPUT
E2 K51 20DB/YL AUTOMATIC SHUT DOWN RELAY CONTROL
E3 - E4 A14 18RD/WT FUSED B(+)
E5 A14 18RD/WT FUSED B(+)
FUSES
A/C COMPRESSOR CLUTCH RELAY
AUTOMATIC SHUT DOWN RELAY
CAV CIRCUIT FUNCTION
B1 T40 14BR ENGINE STARTER MOTOR RELAY OUTPUT
B2 K90 20TN ENGINE STARTER MOTOR RELAY CONTROL
B3 - B4 A41 14YL FUSED IGNITION SWITCH OUTPUT (START)
B5 A1 14RD FUSED B(+)
ENGINE STARTER MOTOR RELAY
78
Page 83
CONNECTOR PINOUTS
CAV CIRCUIT FUNCTION
C1 A141 16DG/WT FUEL PUMP RELAY OUTPUT
C2 K31 20BR FUEL PUMP RELAY CONTROL
C3 - C4 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
C5 A14 18RD/WT FUSED B(+)
CAV CIRCUIT FUNCTION
F1 C25 12YL HIGH SPEED RADIATOR FAN RELAY OUTPUT
F2 C27 20DB/PK HIGH SPEED RADIATOR FAN RELAY CONTROL
F3 - F4 F18 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
F5 A16 12GY FUSED B(+)
CAV CIRCUIT FUNCTION
A1 X2 20DG/RD HORN RELAY OUTPUT
A2 X3 20BK/RD HORN RELAY CONTROL
A3 - A4 F62 20RD FUSED B(+)
A5 F62 20RD FUSED B(+)
CAV CIRCUIT FUNCTION
25 F18 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
26 C23 12DG LOW SPEED RADIATOR FAN RELAY OUTPUT
27 - 28 A16 12GY FUSED B(+)
29 C24 20YL/RD LOW SPEED RADIATOR FAN RELAY CONTROL
CAV CIRCUIT FUNCTION
G1 T16 16RD TRANSMISSION CONTROL RELAY OUTPUT
G2 Z1 20BK GROUND
G3 - G4 T15 20LG TRANSMISSION CONTROL RELAY CONTROL
G5 A30 16RD/WT FUSED B(+)
FUEL PUMP RELAY
HIGH SPEED RADIATOR FAN RELAY
HORN RELAY
LOW SPEED RADIATOR FAN RELAY
TRANSMISSION CONTROL RELAY
C
O
N
N
E
C
T
O
R
P
I
N
O
U
T
S
79
Page 84
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
PUMP MOTOR CONNECTOR (CONNECTOR SIDE)
1 TN GROUND
2 RD PUMP/MOTOR RELAY OUTPUT
RIGHT FRONT WHEEL SPEED SENSOR - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 B7 18WT RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 B6 18WT/DB RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
P
I
N
O
U
T
S
CAV CIRCUIT FUNCTION
RIGHT FRONT WHEEL SPEED SENSOR (SENSOR SIDE)
1 WT RIGHT FRONT WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 WT/DB RIGHT FRONT WHEEL SPEED SENSOR SIGNAL
80
Page 85
CONNECTOR PINOUTS
CAV CIRCUIT FUNCTION
RIGHT REAR WHEEL SPEED SENSOR - BLACK 2 WAY
1 B2 20YL RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 B1 20YL/DB RIGHT REAR WHEEL SPEED SENSOR SIGNAL
RIGHT REAR WHEEL SPEED SENSOR (SENSOR SIDE)
CAV CIRCUIT FUNCTION
1 YL RIGHT REAR WHEEL SPEED SENSOR 12 VOLT SUPPLY
2 YL/DB RIGHT REAR WHEEL SPEED SENSOR SIGNAL
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
TRACTION CONTROL SWITCH - WHITE 4 WAY
1- 2 B27 20RD/YL TRACTION CONTROL SWITCH SENSE
3 Z1 20BK GROUND
4 E2 22OR PANEL LAMPS DRIVER
P
I
N
O
U
T
S
81
Page 86
CONNECTOR PINOUTS
C
O
N
N
E
C
T
O
R
CAV CIRCUIT FUNCTION
TRACTION CONTROL SWITCH (SWITCH SIDE)
1- 2 RD/YL TRACTION CONTROL SWITCH SENSE
3 BK GROUND
4 OR PANEL LAMPS DRIVER
P
I
N
O
U
T
S
82
Page 87
10.0 SCHEMATIC DIAGRAMS
SCHEMATICS
S
C
H
E
M
A
T
I
C
S
83
Page 88
NOTES
S
C
H
E
M
A
T
I
C
S
84
Loading...