1998 ISUZU TROOPER Wiring

5A±2
BRAKE CONTROL SYSTEM
Chart B-16 FL Speed Sensor Disconnection
(DTC 51) 5A±50. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-17 FR Speed Sensor Disconnection
(DTC 52) 5A±50. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-18 RL Speed Sensor Disconnection
(DTC 53) 5A±51. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-19 RR Speed Sensor Disconnection
(DTC 54) 5A±51. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-20 FL Speed Sensor Short Circuit
(DTC 61) 5A±52. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-21 FR Speed Sensor Short Circuit
(DTC 62) 5A±53. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-22 RL Speed Sensor Short Circuit
(DTC 63) 5A±54. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-23 RR Speed Sensor Short Circuit
(DTC 64) 5A±55. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-24 Sensor Signal Input Abnormality
(DTC 65) 5A±56. . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensor Signal Abnormality Criteria using
TECH 2 5A±56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Inspection Procedure 5A±57. . . . . . . . . . . . . . . .
Chart C-1-1 FL Sensor Output Inspection
Procedure 5A±57. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart C-1-2 FR Sensor Output Inspection
Procedure 5A±58. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart C-1-3 RL Sensor Output Inspection
Procedure 5A±58. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart C-1-4 RR Sensor Output Inspection
Procedure 5A±59. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart TC-1 Sensor Output Inspection
Procedure (Use TECH 2) 5A±59. . . . . . . . . . . . . .
Chart C-2 Transmission Input Inspection
Procedure 5A±60. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart TC-2 Transmission Input Inspection
Procedure (Use TECH 2) 5A±61. . . . . . . . . . . . . .
Special Tools 5A±62. . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
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.

5A±5 BRAKE CONTROL SYSTEM
FR
Front Right
GEN
Generator
MV
Millivolts
RL
Rear Left
RR
Rear RightRPS
Revolution per Second
VDC
Volts DC
VA C
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
ªBASIC DIAGNOSTIC FLOWCHARTº and repair.
Please refer to Section 5C 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.
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
Powertrain 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 (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 ªONº position.
Before removing or connecting battery cables, fuses or
connectors, always turn the ignition switch to the ªOFFº
position.
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 toobserve 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 and valve block
connectors should be disconnected before the
welding operation begins.

The EHCU and valve block connectors should never
be connected or disconnected with the ignition ªONº .

EHCU of the Anti-lock Brake System are not
separately serviceable and must be replaced as
assemblies. Do not disassemble any component
which is designated as non-serviceable in this
Section.

If only rear wheels are rotated using jacks or drum
tester, the system will diagnose a speed sensor
malfunction and the ªABSº warning light will
illuminate. But actually no trouble exists. After
inspection stop the engine once and re-start it, then
make sure that the ªABSº 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
(40A). 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 ªmost likelyº 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.

5A±39 BRAKE CONTROL SYSTEM
Diagnostic Trouble Codes
Choose and trace an appropriate flowchart by the
numbers listed below to find fault and repair.
Code
ItemDiagnosisChart No.
12Start CodeNormalÐ
14EHCU FunctionAbnormality in input/output, operational and
control circuitsB-2
15Power Voltage DropB-3
16CLASS±2 Communication Line Ab-
normalityB-4
21G-sensorWiring disconnectionB-5
23Transmission InputInput abnormalityB-6
24Transfer MonitorB-7
32Motor & Motor RelayShorted or disconnected coilB-8
35Valve RelayShorted or disconnected coil/wiringB-9
41FL Holding Solenoid ValveShorted or disconnected coil/wiringB-10
42FL Decompression Solenoid ValveShorted or disconnected coil/wiringB-11
43FR Holding Solenoid ValveShorted or disconnected coil/wiringB-12
44FR Decompression Solenoid ValveShorted or disconnected coil/wiringB-13
45Rear Holding Solenoid ValveShorted or disconnected coil/wiringB-14
46Rear Decompression Solenoid ValveShorted or disconnected coil/wiringB-15
51FL Wheel Speed SensorDisconnected coil/wiringB-16
52FR Wheel Speed SensorDisconnected coil/wiringB-17
53RL Wheel Speed SensorDisconnected coil/wiringB-18
54RR Wheel Speed SensorDisconnected coil/wiringB-19
61FL Wheel Speed SensorShorted coil/wiringB-20
62FR Wheel Speed SensorShorted coil/wiringB-21
63RL Wheel Speed SensorShorted coil/wiringB-22
64RR Wheel Speed SensorShorted coil/wiringB-23
65Sensor Signal InputWrong number of teethB-24

5A±56
BRAKE CONTROL SYSTEM
Chart B-24 Sensor Signal Input Abnormality (DTC 65)
StepActionYe sNo
1Using TECH 2?Go to Step 2Go to Step 3
21. Connect TECH 2.
2. Select Snap shot manual trigger.
3. With wheel speed data displayed, run the vehicle when speed
has arrived at 30 km/h (18 mph).
4. Check speed data on each wheel (refer to the criterion given
below). *1
Is the abnormal sensor condition found?
Replace.
Go to Step 8
Go to Step 3
All the sensors
should follow the
following
flowchart (without
using TECH 2).
3Is there play in sensor/sensor ring?Repair.
Go to Step 8
Go to Step 4
4Is there powdered iron sticking to sensor/sensor ring?Repair.
Go to Step 8
Go to Step 5
5Is there a broken tooth or indentation in sensor ring?Replace sensor
ring.
Go to Step 8
Go to Step 6
6Is there play in wheel bearing?Adjust or repair.
Go to Step 8
Go to Step 7
7Is the check wiring between sensor and EHCU normal?
Replace EHCU.
Go to Step 8
Repair, and
perform system
self-check.
Go to Step 8
81. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat ªBasic
diagnostic flow
chart.º
Go to Step 8
Sensor Signal Abnormality Criteria using
TECH 2
1. While driving, the speed of one or two wheels 25% or
more higher than that of the other wheels.
2. The speed of one or two wheels is 10 km/h (6 mph) or
more higher than that of the other wheels.
3. During steady driving, wheel speed changes abruptly.
*1 The vehicle must run on a level paved road.
NOTE: Even after repairing the faulty part the warning
light (W/L) does not go out if the vehicle is at a stop.
Turn the ignition switch to the ON position and drive the
vehicle at 12 km/h or higher to make sure that the warning
light goes out.
It is important to verify that the correct tires are installed
on vehicle.

5B±1 ANTI±LOCK BRAKE SYSTEM
BRAKES
ANTI-LOCK BRAKE SYSTEM
CONTENTS
Service Precaution 5B±1. . . . . . . . . . . . . . . . . . . . . .
Electronic Hydraulic Control Unit 5B±2. . . . . . . . . .
Electronic Hydraulic Control Unit and
Associated Parts 5B±2. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5B±2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
G-Sensor 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±3. . . . . . . . . . . . . . . . . .
Installation 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Wheel Speed Sensor 5B±4. . . . . . . . . . . . . . . Front Wheel Speed Sensor and
Associated Parts 5B±4. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±5. . . . . . . . . . . . . . . . . .
Installation 5B±5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Wheel Speed Sensor 5B±6. . . . . . . . . . . . . . .
Rear Wheel Speed Sensor and
Associated Parts 5B±6. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±6. . . . . . . . . . . . . . . . . .
Installation 5B±6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM(SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
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.CAUTION: Re place all components included in
repair kits used to service this system. Lubricate
rubber parts with clean, fresh brake fluid to ease
assembly. Do not use shop air with in±line
lubricators on brake parts, as damage to rubber
components may result. If any hydraulic component
is removed or brake line disconnected, it may be
necessary to bleed part or all of the brake system.
NOTE: The use of rubber hoses or parts other than those
furnished specifically for the Anti±lock Brake System may
lead to functional problems requiring major overhaul.

5B±3 ANTI±LOCK BRAKE SYSTEM
G-Sensor
Removal
350RX001
1. Remove center console.

Refer to Consoles in Body and Accessories
section.
2. Remove clip from G-sensor connector (1), then
disconnect connector.
3. Remove G-sensor assembly fixing bolt (2).
4. Remove G-sensor assembly (3).
Inspection and Repair
Refer to Chart B-5 in Brake Control System section.
Installation
1. Install G-sensor assembly (3).

Care should be taken so that the G-sensor is not
installed in the wrong direction.
2. Install G-sensor assembly fixing bolt (2).

Tighten the fixing bolt to the specified torque.
Torque : 10 N´m (1.0kg´m/87 lb in)
3. Install G-sensor wiring connector (1).
4. Install center console.

Refer to Consoles in Body and Accessories
section.

5C – 2 POWER ASSISTED BRAKE SYSTEM
Front Disc Brakes ........................................................................................................... 5C-47
Brake Pads Replacement .......................................................................................... 5C-47
Caliper Replacement ................................................................................................. 5C-50
Rebuilding the Caliper ............................................................................................... 5C-53
Rear Disc Brakes ............................................................................................................ 5C-56
Brake Pads Replacement .......................................................................................... 5C-56
Caliper Replacement ................................................................................................. 5C-59
Rebuilding the Caliper ............................................................................................... 5C-62
Unit Repair .......................................................................................................................... 5C-65
Master Cylinder .............................................................................................................. 5C-65
Vacuum Booster ............................................................................................................. 5C-67
SERVICE PRECAUTION
WARNING:
IF SO EQUIPPED WITH A SUPPLEMENTAL RESTRAINT SYSTEM (SRS), REFER TO THE SRS COMPONENT
AND WIRING LOCATION VIEW IN ORDER TO DETERMINE WHETHER YOU ARE PERFORMING SERVICE ON
OR NEAR THE SRS COMPONENTS OR THE SRS WIRING. WHEN YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS WIRING, REFER TO THE SRS SERVICE INFORMATION.
FAILURE TO FOLLOW WARNINGS COULD RESULT IN POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
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 specification. Following these instructions can help you avoid damage to
parts and systems.

PARKING BRAKES 5D Ð 1
SECTION 5D
PARKING BRAKES
CONTENTS
PAGE
Service Precaution .............................................................................................................5D- 1
Main Data and Specifications ........................................................................................... 5D- 2
Service Standard................................................................................................................ 5D- 2
Servicing ............................................................................................................................. 5D- 3
Fixing Torque ...................................................................................................................... 5D- 5
General Description ........................................................................................................... 5D- 6
On-Vehicle Service .............................................................................................................5D- 7
Parking Brake Lever Replacement ............................................................................... 5D- 7
Parking Brake Cable ...................................................................................................... 5D- 9
SERVICE PRECAUTION
WARNING:
IF SO EQUIPPED WITH A SUPPLEMENTAL RESTRAINT SYSTEM (SRS), REFER TO THE SRS COMPONENT
AND WIRING LOCATION VIEW IN ORDER TO DETERMINE WHETHER YOU ARE PERFORMING SERVICE ON
OR NEAR THE SRS COMPONENTS OR THE SRS WIRING. WHEN YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS WIRING, REFER TO THE SRS SERVICE INFORMATION.
FAILURE TO FOLLOW WARNINGS COULD RESULT IN POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
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 specification. Following these instructions can help you avoid damage to
parts and systems.