ISUZU NKR, NPR, NQR Service Manual
WORKSHOP MANUAL
NKR . NPR . NQR
ANTI-LOCK BRAKE SYSTEM
(ABS)
SECTION 5A4
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-1
HOME
SECTION 5A4
ANTI-LOCK BRAKE SYSTEM (ABS)
Service Precaution
CAUTION: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY
the exact part number for that application. ISUZU will call out those fasteners that require a replacement
after removal. ISUZU will also call out the fasteners that require thread lockers or thread sealant. UNLESS
OTHERWISE SPECIFIED, do not use supplemental coatings (Paints, greases, or other corrosion inhibitors)
on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener
torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following these instructions can help you avoid damage to
parts and systems.
CONTENTS
PAGE
Service Precaution..........................................................................................................5A4 -1
General Description ........................................................................................................5A4 -5
System Components..................................................................................................5A4 -6
Electronic Hydraulic Control Unit (EHCU)................................................................5A4 -6
Hydraulic Unit (HU).....................................................................................................5A4 -6
ABS Warning Light.....................................................................................................5A4 -6
Wheel Speed Sensor ..................................................................................................5A4 -6
Normal and Anti-lock Braking....................................................................................5A4 -6
Brake Pedal Travel......................................................................................................5A4 -7
Acronyms and Abbreviations ....................................................................................5A4 -7
General Diagnosis...........................................................................................................5A4 -7
General Information....................................................................................................5A4 -7
ABS Service Precautions...........................................................................................5A4 -7
Computer System Service Precautions....................................................................5A4 -7
General Service Precautions.....................................................................................5A4 -8
Note on Intermittents..................................................................................................5A4 -8
Test Driving ABS Complaint Vehicles.......................................................................5A4 -8
“ABS” Warning Light..................................................................................................5A4 -8
Normal Operation .......................................................................................................5A4 -8
Basic Diagnostic Flow Chart .....................................................................................5A4 -9
Basic Inspection Procedure.......................................................................................5A4 -9
5A4-2 ANTI-LOCK BRAKE SYSTEM (ABS)
Tech 2 Scan Tool ........................................................................................................5A4 -10
Tech 2 Features ..........................................................................................................5A4 -11
Getting Started............................................................................................................5A4 -11
Operating Procedure (For Example).........................................................................5A4 -12
DTC Modes..................................................................................................................5A4 -13
DTC Information Mode ...............................................................................................5A4 -13
Plotting Snapshot Graph............................................................................................5A4 -14
Plotting Graph Flow Chart (Plotting graph after obtaining vehicle information)..5A4 -15
Flow Chart for Snapshot Replay (Plotting Graph) ...................................................5A4 -16
Tech 2 Data Display....................................................................................................5A4 -17
Special Function.........................................................................................................5A4 -17
EHCU Connector Pin-out Checks..............................................................................5A4 -21
Circuit Diagram...........................................................................................................5A4 -22
Connector List ............................................................................................................5A4 -26
Part Location...............................................................................................................5A4 -29
Symptom Diagnosis........................................................................................................5A4 -30
Chart A-1 ABS Works Frequently But Vehicle Does Not Decelerate......................5A4 -30
Chart TA-1 ABS Works Frequently But Vehicle
Does Not Decelerate (Use TECH 2)...........................................................................5A4 -30
Chart A-2 Uneven Braking Occurs While ABS Works.............................................5A4 -31
Chart A-3, TA-3 The Wheels Are Locked...................................................................5A4 -31
Chart A-4 Brake Pedal Feed Is Abnormal .................................................................5A4 -32
Chart A-5, TA-5 Braking Sound (From Hydraulic Unit)
Is Heard While Not Braking........................................................................................5A4 -33
Diagnostic Trouble Codes..............................................................................................5A4 -34
Diagnosis By “ABS” Warning Light Illumination Pattern ............................................5A4 -35
Diagnostic Trouble Codes (DTCs).............................................................................5A4 -35
Chart B-1-1 With the key in the ON position (Before starting the engine).
Warning light (W/L) is not activated..........................................................................5A4 -39
Chart 1 (DTC 13/C0213) Vehicle Type Error..............................................................5A4 -40
Chart 2 (DTC 14/C0214) Low Power Voltage of
Rear Sensor or EHCU Abnormality ...........................................................................5A4 -40
Chart 3 (DTC 15/C0215) Low Power Voltage OUT of Range ...................................5A4 -41
Chart 4 (DTC 25/C0225) Exhaust Brake Cut Circuit Abnormality ...........................5A4 -42
Chart 5 (DTC 33/C0233) Motor Drive Circuit Abnormality .......................................5A4 -42
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-3
Chart 6 (DTC 34/C0234) Abnormal Motor Rotation..................................................5A4 -42
Chart 7 (DTC 41/C0241) Solenoid Valve Power Supply Abnormality .....................5A4 -43
Chart 8 (DTC 43, 45/C0243, C0245) Solenoid Valve Circuit Abnormality...............5A4 -43
Chart 9 (DTC 51/C0251) FL Speed Sensor Circuit Abnormality..............................5A4 -43
Chart 10 (DTC 52/C0252) FR Speed Sensor Circuit Abnormality............................5A4 -43
Chart 11 (DTC 53/C0253) RL Speed Sensor Circuit Abnormality............................5A4 -44
Chart 12 (DTC 54/C0254) RR Speed Sensor Circuit Abnormality...........................5A4 -45
Chart 13 (DTC 61/C0261) Abnormal FL Speed Sensor Signal.................................5A4 -46
Chart 14 (DTC 62/C0262) Abnormal FR Speed Sensor Signal................................5A4 -48
Chart 15 (DTC 63/C0263) Abnormal RL Speed Sensor Signal................................5A4- 50
Chart 16 (DTC 64/C0264) Abnormal RR Speed Sensor Signal................................5A4- 51
Chart 17 (DTC 65/C0265) Tire Size Error...................................................................5A4- 52
Unit Inspection Procedure..............................................................................................5A4- 53
Chart C-1-1 FL Speed Sensor Output Inspection Procedure..................................5A4- 53
Chart C-1-2 FR Speed Sensor Output Inspection Procedure..................................5A4- 54
Chart C-1-3 RL Speed Sensor Output Inspection Procedure..................................5A4- 55
Chart C-1-4 RR Speed Sensor Output Inspection Procedure.................................5A4- 57
Chart TC-1 Sensor Output Inspection Procedure (Use TECH 2) ............................5A4- 58
Electronic Hydraulic Control Unit (EHCU).....................................................................5A4- 59
Removal.......................................................................................................................5A4- 59
Installation...................................................................................................................5A4- 59
Front Speed Sensor ........................................................................................................5A4- 60
Front Speed Sensor and Associated Parts ..............................................................5A4- 60
Removal.......................................................................................................................5A4- 60
Inspection and Repair ................................................................................................5A4- 60
Installation...................................................................................................................5A4- 60
Front Speed Sensor Rotor..............................................................................................5A4- 61
Front Speed Sensor Rotor and Associated Parts....................................................5A4- 61
Removal.......................................................................................................................5A4- 61
Inspection and Repair ................................................................................................5A4- 62
Installation...................................................................................................................5A4- 62
Rear Speed Sensor .........................................................................................................5A4- 6 3
Rear Speed Sensor and Associated Parts................................................................5A4- 63
Removal.......................................................................................................................5A4- 64
Inspection and Repair ................................................................................................5A4- 64
5A4-4 ANTI-LOCK BRAKE SYSTEM (ABS)
Installation...................................................................................................................5A4- 64
Rear Speed Sensor Rotor...............................................................................................5A4- 65
Rear Speed Sensor Rotor and Associated Parts.....................................................5A4- 65
Removal.......................................................................................................................5A4- 65
Inspection and Repair ................................................................................................5A4- 65
Installation...................................................................................................................5A4- 65
Special Tools ...................................................................................................................5A4- 67
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-5
General Description
The Anti-lock Brake System (ABS) works on all four
wheels. A combination of wheel speed sensor and
Electronic Hydraulic Control Unit (EHCU) can
ABS
9
6
CAB
DIAG
TO EHCU
10
TO EHCU
1
2
4
3
EHCU
EXH BRAKE CUT RELAY
ELECTRONIC HYDRAULIC
CONTROL UNIT(EHCU)
HYDRAULIC UNIT(HU)
determine when a wheel is about to stop turning and
adjust brake pressure to maintain best braking.
This system helps the drive maintain greater control of
the vehicle under heavy braking conditions.
ENGINE CONTROLLER
OR
TO EHCU
5
7
4
8
Legend
(1) Hydraulic Line (7) Load Sensing Proportioning Valve (LSPV)
(2) Electronic Line (8) Battery
(3) Electronic Hydraulic Control Unit (EHCU) (9) ABS Warning Light
(4) Front Wheel Speed Sensor (10) Brake Switch
(5) Rear Wheel Speed Sensor
(6) Diagnosis Connector
5
5A4-6 ANTI-LOCK BRAKE SYSTEM (ABS)
System Components
The Anti-lock Brake System consists of a Electronic
Hydraulic Control Unit (EHCU), four Wheel Speed
Sensors and Warning Light.
Electronic Hydraulic Control Unit (EHCU)
The EHCU consists of Electronic Brake Control
Module (EBCM) and Hydraulic Unit (HU).
The EHCU is located at the frame side, in front of rear
spring bracket.
The EHCU consists of ABS control circuits, fault
detector, and a fail-safe. It drives the hydraulic unit
according to the signal from each sensor, cancelling
ABS to return to normal braking when a malfunction
has occurred in the ABS.
The EHCU is self-diagnosing function which can
indicate faulty circuits during diagnosis.
CONNECTOR
EHCU
Tang lock
PushPush
Lever
Move lever outside
ABS Warning Light
Vehicles equipped with the Anti-lock Brake System
has an amber “ABS” warning light in the instrument
panel. The “ABS” warning light will illuminate if a
malfunction in the Anti-lock Brake System is detected
by the Electronic Hydraulic Control Unit (EHCU). In
case of an electronic malfunction, the EHCU will turn
“ON” the “ABS” warning light and disable the Anti-lock
braking function.
The “ABS” light will turn “ON” for 2 seconds after the
ignition switch is to the “ON” position, and then will go
out.
If the “ABS” light comes “ON” and stays “ON” while
driving, the Anti-lock Brake System should be
inspected for a malfunction according to the diagnosis
procedure.
NOTE:
When disconnecting harness connector from EHCU,
push the tang lock of the connector (
release the tang lock. Then move the lever.
portion) and
Hydraulic Unit (HU)
It consists of a Motor, Plunger Pump, Solenoid Valves
and Check Valve.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear drum
brakes according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that
returns from the front and rear wheel brake so that
pressure of front wheel brake can be reduced
smoothly.
Plunger Pump: Feeds the brake fluid held in the
reservoir to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU. Check Valve: Controls the brake fluid flow.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is
attached to the knuckle on the front wheels and to the
bracket on the brake back plate on the rear wheels.
The front speed sensor is coil type and rear is Hall IC
type.
The sensor rotors press-fitted to front and rear wheel
hubs output pulse frequency depending on wheel
rotation.
The speed sensors find vehicle speed from its
frequency.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power
assisted brake system. However, with the detection of
wheel lock-up, a slight bump or kick-back will be felt in
the brake pedal. This pedal “bump” will be followed by
a series of short pedal pulsations which occurs in rapid
succession. The brake pedal pulsation will continue
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-7
until there is no longer a need for the anti-lock function
or until the vehicle is stopped. A slight ticking or
popping noise may be heard during brake applications
when the Anti-lock features is being used.
When the Anti-lock feature is being used, the brake
pedal may rise even as the brakes are being applied.
This is also normal. Maintaining a consist force on the
pedal will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System
may be stopped by applying normal force to the brake
pedal. Although there is no need to push the pedal
beyond the point where it stops or holds the vehicle, by
applying more force the pedal will continue to travel
toward the floor.
This extra brake pedal travel is normal.
Acronyms and Abbreviations
Several acronyms and abbreviations are commonly
used throughout this section:
ABS
Anti-lock Brake System
CKT
Circuit
DLC
Data Link Connector
DTC
Diagnostic Trouble Code
DVM
Digital Volt Meter (High Impedance Multimeter)
EHCU
Electronic Hydraulic Control Unit
FL
Front Left
FR
Front Right
GEN
Generator
HU
Hydraulic Unit
MV
Millivolts
RL
Rear Left
RR
Rear Right
RPS
Revolution per Second
SW
Switch
VDC
Volts DC
VAC
Volts AC
W/L
Warning Light
WSS
Wheel Speed Sensor
General Diagnosis
General Information
ABS malfunction can be classified into two types,
those which can be detected by the ABS warning light
and those which can be detected as a vehicle
abnormality by the driver.
In either case, locate the fault in accordance with the
“BASIC DIAGNOSTIC FLOWCHART” and repair.
Please refer to Section 5A for the diagnosis of
mechanical troubles such as brake noise, brake judder
(brake pedal or vehicle vibration felt when braking),
uneven braking, and parking brake trouble.
ABS Service Precautions
Required Tools and Items:
• Box Wrench
• Brake Fluid
• Special Tool
Some diagnosis procedures in this section require the
installation of a special tool.
5-8840-0285-0 (J-39200) High Impedance
Multimeter
When circuit measurements are requested, use a
circuit tester with high impedance.
Computer System Service Precautions
The Anti-lock Brake System interfaces directly with the
Electronic Hydraulic Control Unit (EHCU) which is a
control computer that is similar in some regards to the
Engine Control Module. These modules are designed
to withstand normal current draws associated with
vehicle operation. However, care must be taken to
avoid overloading any of the EHCU circuits. In testing
for opens or shorts, do not ground or apply voltage to
any of the circuits unless instructed to do so by the
appropriate diagnostic procedure. These circuits
should only be tested with a high impedance
multimeter 5-8840-0285-0 (J-39200) or special tools
as described in this section. Power should never be
removed or applied to any control module with the
ignition in the “ON” position. Before removing or
connecting battery cables, fuses or connectors, always
turn the ignition switch to the “OFF” position.
5A4-8 ANTI-LOCK BRAKE SYSTEM (ABS)
General Service Precautions
The following are general precautions which should be
observed when servicing and diagnosing the Anti-lock
Brake System and/or other vehicle systems. Failure to
observe these precautions may result in Anti-lock
Brake System damage.
• If welding work is to be performed on the vehicle
using an electric arc welder, the EHCU connector
should be disconnected before the welding
operation begins.
• The EHCU connector should never be connected
or disconnected with the ignition “ON”.
• The EHCU is not separately serviceable and must
be replaced as assemblies. Do not disassemble
any component which is designated as nonserviceable in this Section.
• If only rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the “ABS” warning light will
illuminate. But actually no trouble exists. After
inspection stop the engine once and re-start it, then
make sure that the “ABS” warning light does not
illuminate.
If the battery has been discharged
The engine may stall if the battery has been
completely discharged and the engine is started via
jumper cables. This is because the Anti-lock Brake
System (ABS) requires a large quantity of electricity. In
this case, wait until the battery is recharged, or set the
ABS to a non-operative state by removing the fuse for
the ABS. After the battery has been recharged, stop
the engine and install the ABS fuse. Start the engine
again, and confirm that the ABS warning light does not
light.
Note on Intermittents
As with virtually any electronic system, it is difficult to
identify an intermittent failure. In such a case
duplicating the system malfunction during a test drive
or a good description of vehicle behavior from the
customer may be helpful in locating a “most likely”
failed component or circuit. The symptom diagnosis
chart may also be useful in isolating the failure. Most
intermittent problems are caused by faulty electrical
connections or wiring. When an intermittent failure is
encountered, check suspect circuits for:
• Suspected harness damage.
• Poor mating of connector halves or terminals not
fully seated in the connector body (backed out).
• Improperly formed or damaged terminals.
Test Driving ABS Complaint Vehicles
In case that there has been an malfunction in the
lighting pattern of “ABS” warning light, the fault can be
located in accordance with the “DIAGNOSIS BY “ABS”
WARNING LIGHT ILLUMINATION PATTERN”. In
case of such trouble as can be detected by the driver
as a vehicle symptom, however, it is necessary to give
a test drive following the test procedure mentioned
below, thereby reproducing the symptom for trouble
diagnosis on a symptom basis:
1. Start the engine and make sure that the “ABS” W/L
goes OFF. If the W/L remains ON, it means that
the Diagnostic Trouble Code (DTC) is stored.
Therefore, read the code and locate the fault.
2. Start the vehicle and accelerate to about 30km/h
(19 mph) or more.
3. Slowly brake and stop the vehicle completely.
4. Then restart the vehicle and accelerate to about 40
km/h (25 mph) or more.
5. Brake at a time so as to actuate the ABS and stop
the vehicle.
6. Be cautious of abnormality during the test. If the
W/L is actuated while driving, read the DTC and
locate the fault.
7. If the abnormality is not reproduced by the test,
make best efforts to reproduce the situation
reported by the customer.
8. If the abnormality has been detected, repair in
accordance with the “SYMPTOM DIAGNOSIS”.
NOTE:
• Be sure to give a test drive on a wide, even road
with little traffic.
• If an abnormality is detected, be sure to suspend
the test and start trouble diagnosis at once.
“ABS” Warning Light
When ABS trouble occurs and actuates when possible
the “ABS” warning light, the trouble code
corresponding to the trouble is stored in the EHCU.
Only the ordinary brake system is available when the
ABS is turned OFF. When the “ABS” warning light is
actuated, if the starter switch is set ON after setting it
OFF once, the EHCU checks up on the entire system
and, if there is no abnormality, judges ABS to work
currently and the warning light works normally even
though the trouble code is stored.
NOTE: Illumination of the “ABS” warning light indicates
that anti-lock braking is no longer available. Power
assisted braking without anti-lock control is still
available.
Normal Operation
“ABS” Warning Light
When the ignition is first moved from “OFF” to “ON”,
the amber “ABS” warning light will turn “ON” for 2
seconds and will turn “OFF”.
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-9
Basic Diagnostic Flow Chart
Step Action Yes No
1 1. Customer complaint.
2. Questioning to customer.
3. Basic inspection (Refer to “Basic inspection procedure”)
Using TECH 2?
2 Make sure of DTC by TROUBLE CODE.
Is EHCU including DTC?
3 Check if the DTC is stored.
Is EHCU including DTC?
4 Test drive.
Is W/L lit?
5 1. Repair of faulty part.
2. Elimination of DTC.
3. Inspection of “ABS” W/L illumination pattern with ignition
SW “ON”.
4. Test drive.
Does repeat trouble?
6 1. Reconnect all components and ensure all components
are properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Go to Step 2 Go to Step 3
Go to Step 5 Go to Step 4
Go to Step 5 Go to Step 4
Go to Step 5 Trouble diagnosis
based on symptom
(Refer to
“SYMPTOM
DIAGNOSIS”) Go
to Step 5
Repeat the
diagnosis of the
symptom or DTC
appears again Go
to Step 1
Finished Go to Step 6
Go to Step 6
Basic Inspection Procedure
1. Basic Inspection of Service Brake
Step Action Yes No
1 Is the fluid level normal? Go to Step 2 Replenish with
fluid.
Go to Step 2
2 Does fluid leak? Repair.
Go to Step 3
3 Is the booster functioning normal? Go to Step 4 Repair.
4 Is the pad and rotor normal? Go to Step 5 Repair.
5 Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
2. Ground Inspection
Step Action Yes No
1 Are ABS-related ground points ok? Go to Step 2 Repair.
2 Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
Finished Go to Step 5
Finished Go to Step 2
Go to Step 3
Go to Step 4
Go to Step 5
Go to Step 2
5A4-10 ANTI-LOCK BRAKE SYSTEM (ABS)
Tech 2 Scan Tool
From 98 MY, Isuzu dealer service departments are
recommended to use Tech 2. Please refer to Tech 2
scan tool user guide.
Legend
(1) PCMCIA Card (4) DLC Cable
(2) RS 232 Loop Back Connector (5) Tech-2
(3) SAE 16/19 Adapter
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-11
Tech 2 Features
1. Tech 2 is a 12 volt system. Do not apply 24 volt.
2. After connecting and/or installing the Vehicle
Communications Interface (VCI) module, PCMCIA
card and DLC connector to the Tech 2, connect
the tool to the vehicle DLC.
3. Make sure the Tech 2 is powered OFF when
removing or installing the PCMCIA card.
4. The PCMCIA card has a capacity of 10 Megabytes
which is 10 times greater than the memory of the
Tech 1 Mass Storage Cartridge.
5. The Tech 2 has the capability of two snapshots.
6. The PCMCIA card is sensitive to magnetism and
static electricity, so care should be taken in the
handling of the card.
7. The Tech 2 can plot a graph when replaying a
snapshot.
8. Always return to the Main Menu by pressing the
EXIT key several times before shutting down.
9. To clear Diagnostic Trouble Codes (DTCs), open
Application Menu and press “F1: Clear DTC Info”.
Getting Started
• Before operating the Isuzu PCMCIA card with the
Tech 2, the following steps must be performed:
1. The Isuzu 2000 Model Year System PCMCIA card
(1) inserts into the Tech 2 (5).
2. Connect the SAE 16/19 adapter (3) to the DLC
cable (4).
3. Connect the DLC cable to the Tech 2 (5).
4. Make sure the vehicle ignition is off.
5. Connect the Tech 2 SAE 16/19 adapter to the
vehicle DLC.
6. Turn on the vehicle ignition.
7. Power the Tech 2 ON and verify the Tech 2 power
up display.
TechTech
2
Press [ENTER] to continue.
Software Version: X.XXX
NOTE: The RS232 Loop back connector is only to use
for diagnosis of Tech 2. Refer to user guide of the
Tech 2.
5A4-12 ANTI-LOCK BRAKE SYSTEM (ABS)
Operating Procedure (For Example)
The power up screen is displayed when you power up
the tester with the Isuzu systems PCMCIA card. Follow
the operating procedure below.
TechTech
2
Press [ENTER] to continue.
Software Version: X.XXX
F0: Diagnostics
F1: Code Index
F2: View Capture Data
F3: Tool Options
F4: Download / Upload Help
(ENTER)
Main Menu
Vehicle Identification
Select one of the following
Vehicle Type (s)
Rodeo/Amigo, Wizard/MU
(UE)
LUV
(TF )
ELF, NPR, NQR
(N∗)
Industrial Engine
(Off-Road)
(N∗) ELF, NPR, NQR
(N∗ENTER)
(1) 2001 (N∗) ELF, NPR, NQR
F0:
F1:
F2:
System Selection Menu
Engine
Chassis
Body
(F2 ENTER)
Vehicle Identification
Select one of the following
ABS
Chassis
3 / 4
(1) 2001
(Y) 2000
(X) 1999
(
W
) 1998
(1) 2001
(F0)
Vehicle Identification
Select one of the following
Model Year(s)
(2000, ENTER)
1 / 4
ABS
1 / 2
(ABS/ASR ENTER)
Menu
• The following table shows which functions are used
for the available equipment versions.
Chassis
(Y) 2000 (N∗) ELF, NPR, NQR
Electronic System: ABS
Partnumber 8972521653
Identifier 00(2WD)
20(4WD)
40(ABS/ASR)
60(12V vehicle)
Partnumer
Confirm
DTC Modes
Chassis
F0:
Diagnostic Trouble Codes
F1:
Data Display
F2: Snapshot
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-13
Diagnostic Trouble Codes
F0:
Read DTC Info Ordered By Priority
F1:
Clear DTC Information
F2: DTC Information
F3: Clear & Reset Vehicle Type
The following is a brief description of each of the sub
menus in DTC Info and DTC. The order in which they
appear here is alphabetical and not necessarily the
way they will appear on the Tech 2.
DTC Information Mode
Use the DTC info mode to search for a specific type of
stored DTC information. There are two choices. The
service manual may instruct the techinician to test for
DTCs in a certain manner. Always follow published
service procedures.
F3: Actuator Test
There are two options available in Tech 2 DTC mode
to display the enhanced information available. After
selecting DTC, the following menu appears.
• DTC Info
• Clear Info
5A4-14 ANTI-LOCK BRAKE SYSTEM (ABS)
When CODE “13” is displayed (Vehicle Type Error)
Step Action Value(s) Yes No
1 Check harness.
Is it okay?
- Erase vehicle
type with TECH
Replace the
harness.
2 and reread
harness
information.
Diagnostic Trouble Codes
F0:
Read DTC Info
F1:
Clear DTC Info
F2: DTC Info
(F3: ENTER)
DTC Status
Current Diagnostic Trouble Codes
This selection will display all DTCs that have failed
during the present ignition cycle.
Clear & Reset Vehicle Type
Do you want clear &
Reset V ehicle Type?
YES
NO
YES: Clear vehicle type and reread vehicle harness
information.
NO: Return
History Diagnostic Trouble Codes
This selection will display only DTCs that are stored in
the EHCU’s history memory.
Plotting Snapshot Graph
This test selects several necessary items from the
data list to plot graphs and makes data comparison on
a long term basis. This test can check ABS
performance and defect by graphing wheel speed
differences between right and left sides, and front and
rear sides obtained from the ABS data list menu.
For trouble diagnosis, you can collect graphic data
(snap shot) directly from the vehicle.
You can replay the snapshot data as needed.
Therefore, accurate diagnosis is possible, even though
the vehicle is not available.
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-15
Plotting Graph Flow Chart (Plotting graph after obtaining vehicle information)
5A4-16 ANTI-LOCK BRAKE SYSTEM (ABS)
Flow Chart for Snapshot Replay (Plotting Graph)
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-17
Tech 2 Data Display
Use the Tech 2 data Values only after the ABS
Diagnostic System Check has been completed, no
DTC(s) were noted, and you have determined that the
on-board diagnostics are functioning properly. Tech 2
values from a properly-running engine may be used for
comparison with the engine you are diagnosing.
ABS Data
Ignition SW is “ON” position.
(For example)
Special Function
There are 12 different menus available for this test.
The state of each circuit can be tested by using these
menus. Especially when DTC cannot be detected, a
faulty circuit can be diagnosed by testing each circuit
by means of these menus.
Even when DTC has been detected, the circuit tests
using these menus could help discriminate between a
mechanical trouble and an electrical trouble.
In all cases test condition; Engine stops with the key
turned to the “ON” position. To be more specific, the
test is conducted with the brake pedal stepped on after
stepping once and releasing.
• Engine: Stop
• Ignition SW: ON
• Brake Pedal: ON-OFF-ON
If the Ignition SW was turned OFF or communication
was lost, make sure to apply the brake pedal ON-OFFON once again and then continue the test.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Left Solenoid Valve Test
F2:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
5A4-18 ANTI-LOCK BRAKE SYSTEM (ABS)
ABS Warning Lamp
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
• The circuit is normal if the warning light in the meter
panel comes on and goes out in accordance with
Tech 2’s instruction.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Left Solenoid Valve Test
F2:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
Exhaust Brake Cut Test
F7:
ABS Relay
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
Make sure of the working sound of the ABS relay.
The circuit is normal if the working sound of the ABS
relay is made in accordance with Tech 2’s instruction.
Actuator Test
ABS Motor
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
Make sure of the working sound of the ABS motor.
The circuit is normal if the working sound of the ABS
motor is made in accordance with Tech 2’s instruction.
Actuator Test
F0:
ABS Relay Test
F2:
Front Left Solenoid Valve Test
F3:
Front Right Solenoid Valve Test
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
Exhaust Brake Cut Relay
Test condition: Engine stops with the key turned to the
“ON” position. To be more specific, the test is
conducted with the brake pedal stepped on after
stepping once and releasing.
Make sure of the working sound of the exhaust brake
cut relay.
The circuit is normal if the working sound of the
exhaust brake cut relay is made in accordance with
Tech 2’s instruction.
Return Pump Relay Test
F1:
Front Left Solenoid Valve Test
F2:
Front Right Solenoid Valve Test
F3:
F4:
Rear Left Solenoid Valve Test
F5:
Rear Right Solenoid Valve Test
F6:
ABS Check Light Test
F7:
Exhaust Brake Cut Test
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Left Solenoid Valve Test
F2:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
ANTI-LOCK BRAKE SYSTEM (ABS) 5A4-19
Hold Valve Test
Purpose: The purpose of this test is to detect brake
pipe and valve line harness wire wrong connections
and valve trouble.
This test will help you confirm the result of your repair
service including the removal/reinstallation of brake
pipe, valve line harness and valve.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
Test conditions: The ignition key is the “ON” position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.
Test procedure:
1. Connect Tech 2 with the vehicle, and select
Special Function from the menus.
2. Select a Hold Valve Menu from the Special
Function Menus.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
Select a Iso Solenoid
from the Front Left Solenoid Valve Test
Function Menus.
Front Left Solenoid Valve Test
Dump Solenoid
3. Press the Hold Valve “ON” Soft Key with the brake
pedal stepped on.
4. Release the brake pedal.
5. Make sure that the Hold Valve “ON” aimed at by
Tech 2 and the wheel locked position are the
same. If different, check brake pipe, valve line
harness wiring and H/UNIT. Repair is needed if
abnormality is found.
6. Conduct Step 2 through Step 5 above on all the
four wheels.
CAUTION: When conducting this test, please
observe the following cautions.
1. Do not start the engine without fail.
2. Lift up the vehicle at the level floor.
•••• Secure a clearance from the floor surface
enough to allow the lifted tire to rotate.
3. Maintain the lift up.
4. Wipe the floor surface to remove water and oil
so that the surface may become unslippery.
5. Do not load the vehicle.
•••• When lifting up the vehicle, be sure to
observe the lifting up points. Refer to
vehicle lifting points in 0A section.
5A4-20 ANTI-LOCK BRAKE SYSTEM (ABS)
Release Valve Test
Purpose: The purpose of this test is to detect brake
pipe and valve line harness wire wrong connections
and valve trouble.
This test will help you confirm the result of your repair
service including the removal/reinstallation of brake
pipe, valve line harness and valve.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
Test conditions: The ignition key is in the “ON” position
with the four wheels lifted up. The brake pedal is
stepped on, released and stepped on again with the
parking brake released.
Select a Dump Solenoid
from the Front Left Solenoid Valve Test
Function Menus.
Front Left Solenoid Valve Test
Iso Solenoid
3. Press the Release Valve “ON” Soft Key with the
brake pedal stepped on.
4. Make sure that the Release Valve “ON” aimed at
by Tech 2 and the wheel released position are the
same. If different, check brake pipe, valve line
harness wiring and H/UNIT. Repair is needed if
abnormality is found.
5. Conduct Step 2 through Step 5 above on all the
four wheels.
Test procedure:
1. Connect Tech 2 with the vehicle, and select
Special Function from the menus.
2. Select a Release Valve Menu from the Special
Function Menus.
Actuator Test
ABS Relay Test
F0:
Return Pump Relay Test
F1:
Front Right Solenoid Valve Test
F3:
Rear Left Solenoid Valve Test
F4:
Rear Right Solenoid Valve Test
F5:
ABS Check Light Test
F6:
Exhaust Brake Cut Test
F7:
CAUTION: When conducting this test, please
observe the following cautions.
1. Do not start the engine without fail.
2. Lift up the vehicle at the level floor.
•••• Secure a clearance from the floor surface
enough to allow the lifted tire to rotate.
3. Maintain the lift up.
4. Wipe the floor surface to remove water and oil
so that the surface may become unslippery.
5. Do not load the vehicle.
•••• When lifting up the vehicle, be sure to
observe the lifting up points. Refer to
vehicle lifting points in 0A section.
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