4WD ISUZU TROOPER 1998 Service Manual PDF

TRANSFER CASE (STANDARD TYPE)
4D1±39
14. Assemble the 2WD±4WD clutch hub and sleeve
assembly (7).
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15. Engage the springs in the same insert with the open
ends away from each other. (Shift On The Fly model)
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16. Place the snap ring (2), a new stopper plate (6) (Shift
On The Fly model) and the clutch sleeve and hub
assembly (7) on the front output shaft (5).
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Legend
(6) Front Output Gear
17. The clutch hub face (with the heavy boss) must be
facing the front output gear side.
18. Use a bench press to slowly force the clutch hub and
sleeve assembly (7) together with the stopper plate
(6) (Shift On The Fly model) into place.
19. Align the inserts with the block ring insert grooves.
Install the block ring (8) (Shift On The Fly model) to
the clutch sleeve and hub assembly (7).
20. Install the outside ring (9) (Shift On The Fly model),
inside ring (10) (Shift On The Fly model) and needle
bearing (12) to the front output gear (11) and bearing
collar (17).
NOTE: C o a t a l l p a r t s w i t h t r a n s mission oil before
installing them.
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TRANSFER CASE (STANDARD TYPE)
4D1±43
Main Data and Specifications
General Specifications
TypeW/Shift On The Fly System model
Synchronized type gears shifting between the 2 and 4 wheel drive mode.
Constant mesh type gears shifting between ªlowº and ªhighº.
WO/Shift On The Fly System model
Constant mesh type gears shifting between the 2 and 4 wheel drive mode,
and between ªlowº and ªhighº.
Control methodW/4WD Switch model
Electric control with the button switch on the instrument panel for gear
shifting between the 2 and 4 wheel drive mode.
Remote control with the gear shift lever on the floor for gear shifting
between ªlow and highº .
WO/4WD Switch model
Remote control with the gear shift lever on the floor for gear shifting.
Gear ratioHigh; 1.000
Low; 2.050
Oil capacity1.45 lit. (1.53 U.S. quart)
Type of lubricantEngine oil
Refer to chart in Section 0
Torque Specifications
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5A±4
BRAKE CONTROL SYSTEM
normal braking when a malfunction has occurred in the
ABS.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment front
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves and Check Valve.
On the outside, the relay box containing a motor relay and
a valve relay is installed.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper 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.
ABS Warning Light
821RW033Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº 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 ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is to the ªONº position.
If the ªABSº light stays ªONº after the ignition switch is the
ªONº position, or comes ªONº and stays ªONº while
driving, the Anti-lock Brake System should be inspected
for a malfunction according to the diagnosis procedure.
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 axle shaft
bearing holder on the rear wheels.
The rotor is press-fit in the axle shaft.The flux generated from electrodes magnetized by a
magnet in the sensor varies due to rotation of the rotor,
and the electromagnetic induction generates alternating
voltage in the coil. This voltage draws a ªsine curveº with
the frequency proportional to rotor speed and it allows
detection of wheel speed.
G-Sensor
The G-sensor installed inside the center console detects
the vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
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 ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue 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 constant 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
EHCU
Electronic Hydraulic Control Unit
FL
Front Left

5A±7 BRAKE CONTROL SYSTEM
Basic Inspection Procedure
1. Basic Inspection of System Brake
StepActionYe sNo
1Is the fluid level normal?
Go to Step 2
Replenish with
fluid.
Go to Step 2
2Does fluid leak?Repair.
Go to Step 3
Go to Step 3
3Is the booster functioning normal?
Go to Step 4
Repair.
Go to Step 4
4Is the pad and rotor normal?
Go to Step 5
Repair.
Go to Step 5
5Reconnect all components and ensure all component are
properly mounted.
Was this step finished?
FinishedGo to Step 5
2. Inspection of Front Axle Switch
StepActionYe sNo
1Turn the key switch on and shift the T/F to 4WD position.
Does the 4WD light come on?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2
3. Ground Inspection
StepActionYe sNo
1Are ABSÐrelated ground points ok?
Go to Step 2
Repair.
Go to Step 2
2Reconnect all components and ensure all components are
properly mounted.
Was this step finished?
FinishedGo to Step 2

5A±11 BRAKE CONTROL SYSTEM
Data List
DisplayContentOK/NG Criteria for Data
Battery VoltageVoltage
Between 10-16.9V
Brake Light SwitchOpen/Close
Open(0V) when pedal is released

Closed(12V) when pedal is depressed.
Front Left Wheel Speed
Front Right Wheel Speed
Rear Left Wheel Speed
Rear Right Wheel SpeedMPH(km/h)
Start the vehicle and make sure of linear change in each
wheel speed.

Turn each wheel by hand and make sure that each
speed data change.
Wheel Sensor StatusOK/NG
To be OK usually
G-sensorLow/High
To be Low usually
Transfer Monitor(TOD)2 Wheel Drive
4 Wheel Drive
When 2WD: 2 Wheel Drive

When 4WD: 4 Wheel Drive
Off-Road Switch
(Transmission Input)
Active/Inactive
When shift lever position is 1, 2 and R: Active (M/T)
(Transmission Input)
When shift lever position is L and R: Active (A/T)
Valve RelayActive/Inactive
To be Active usually
ABS StateON/OFF
To be OFF usually
ABS RelayActive/Inactive
To be Active usually
Return Pump RelayActive/Inactive
To be Inactive usually
Front Left Isolation ValveActive/Inactive
To be Inactive usually
Front Left Dump Valve
Front Right Isolation Valve
Front Right Dump Valve
Rear Isolation Valve
Rear Dump Valve
ABS Warning LampON/OFF
To be ON usually (while engine stopped)

5A±36
BRAKE CONTROL SYSTEM
StepNo Ye s
Action
10Is the input of 4WD controller normal?
Go to Step 11
Replace
controller or
repair harness.
Go to Step 11
11Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 11
Chart TA-1 ABS Works Frequently But Vehicle Does Not Decelerate (Use TECH 2)
StepActionYe sNo
11. Connect TECH 2.
2. Make sure of the output conditions of each wheel speed
sensor by mode ªF1: Data Displayº.
Is the output of each sensor normal?
Go to Step 2
Replace wheel
speed sensor.
Go to Step 3
2Return to Chart A-1.
Was the Chart A-1 finished?
Go to Step 3Go to Step 2
3Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 3
Chart A-2 Uneven Braking Occurs While ABS Works
StepActionYe sNo
1Is there play in each sensor?Repair.
Go to Step 5
Go to Step 2
2Is there damage or powdered iron sticking to each sensor/sensor
ring?Repair.
Go to Step 5
Go to Step 3
3Is the output of each sensor normal? (Refer to chart C-1 or TC-1)
Go to Step 4
Replace sensor
or repair harness.
Go to Step 5
4Is brake pipe connecting order correct?
Replace EHCU.
Go to Step 5
Reconnect brake
pipe correctly.
Go to Step 5
5Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 5
Chart A-3, TA-3 The Wheels Are Locked
StepActionYe sNo
1Is ABS working?Go to Step 2Go to Step 6
2Is vehicle speed under 10 km/h (6mph)?Normal.Go to Step 3
3Is sensor output normal? (Chart C-1 or TC-1)
Go to Step 4
Replace sensor
or repair harness.
Go to Step 9
4Is transmission input normal? (Chart C-2 or TC-2)
Go to Step 5
Replace SW or
repair harness.
Go to Step 9

5A±37 BRAKE CONTROL SYSTEM
StepNo Ye s
Action
5Is front 4WD controller normal?
Replace EHCU.
Go to Step 9
Replace 4WD
controller or
repair harness.
Go to Step 9
6Is transmission input normal? (Chart C-2 or TC-2)
Go to Step 7
Replace SW or
repair harness
Go to Step 9
7Is front 4WD controller normal?
Go to Step 8
Replace 4WD
controller or
repair harness.
Go to Step 9
8Is hydraulic unit grounded properly?Replace EHCU.
Go to Step 9Correct.
Go to Step 9
9Reconnect all components, ensure all components are properly
mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 9
Chart A-4 Brake Pedal Feed Is Abnormal
StepActionYe sNo
1Is the stop light actuated when the brake pedal is depressed?Go to Step 2Go to Step 3
21. Turn the ignition switch off.
2. Disconnected EHCU connector.
3. Measure voltage between the EHCU connector terminal 10
and 15 when brake pedal is depressed.
Is the voltage equal to the battery voltage?
Go to Step 4
Harness NG
between brake
SW and EHCU.
Go to Step 7
3Is stop light fuse C-14 normal?
Go to Step 5
Replace fuse
C-14.
Go to Step 7
4Is there continuity between EHCU connector terminals, 12 and 15
to body ground?
Go to Step 6
Repair body
grounded
harness.
Go to Step 7
5Is the brake SW normal?Repair stop light
harness.
Go to Step 7Replace brake
SW.
Go to Step 7
6Is the check harness/connector for suspended disconnection?Hydraulic system
leakage or air
entry (Refer to
servicing
ªLeakage or
brake fluidº )
Go to Step 7
Repair harness.
Go to Step 7
7Reconnect all components and ensure all components are
properly mounted.
Was this step finished?Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 7

5A±47 BRAKE CONTROL SYSTEM
Chart B-7 Transfer Monitor (DTC 24)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
Is the EHCU connector terminal 9 line normally?
Go to Step 2
Repair
Go to Step 3
2Is the TOD ECU or 4WD controller normal?
Replace EHCU.
Go to Step 3
Repair or replace
TOD ECU or
4WD contrder.
Go to Step 3
31. Reconnect all components, ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 3
Chart B-8 EHCU Pump Motor And Motor Relay Circuit (DTC 32)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 13 and
body ground.
Is the voltage equal to battery voltage?
Go to Step 2
Repair
fuse/harness
between battery
and EHCU
connector
terminal 13.
Go to Step 3
2Is there continuity between EHCU connector terminal 12 and
ground?
Go to Step 3
Repair between
EHCU connector
terminal 12 and
ground.
Go to Step 3
31. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 3
Chart B-9 EHCU Pump Valve And Valve Relay Circuit (DTC 35)
StepActionYe sNo
11. Turn the key off.
2. Disconnect EHCU connector.
3. Measure voltage between EHCU connector terminal 14 and
body ground.
Is the voltage equal to battery voltage?
Replace EHCU.
Go to Step 2
Repair fuse and
harness EHCU
connector
terminal 14 and
battery.
Go to Step 2
21. Reconnect all components and ensure all components are
properly mounted.
2. Clear diagnostic trouble code.
Was this step finished?
Repeat the ªBasic
diagnostic flow
chart.º
Go to Step 2

6E±32
ENGINE DRIVEABILITY AND EMISSIONS
Undercarriage Component Locator
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Undercarriage Component Locator Table (Automatic Transmission)
Number
NameLocation
1Fuel Pump AssemblyInstalled in the top of the fuel tank
2Fuel Gauge UnitInstalled in the front edge of the fuel tank, on
the right side
3Fuel FilterLocated along the inside of the right frame rail,
ahead of the rear axle
4Vehicle Speed Sensor (VSS)2WD: Protrudes from the transmission
housing, just ahead of the propeller shaft.
4WD: Protrudes from the rear output shaft
housing of the transfer case.
5Heated Oxygen Sensor (Bank 1, HO2S 1)Threaded into the exhaust pipe ahead of the
right-hand catalytic converter
6Heated Oxygen Sensor (Bank 2, HO2S 1)Threaded into the exhaust pipe ahead the
left-hand catalytic converter

6E±33 ENGINE DRIVEABILITY AND EMISSIONS
Undercarriage Component Locator Table (Manual Transmission)
Number
NameLocation
1Fuel Pump AssemblyInstalled in the top of the fuel tank
2Fuel Gauge UnitInstalled in the front edge of the right frame
rail, ahead of the rear axle
3Fuel FilterLocated along the inside of the right frame rail,
ahead of the rear axle
4Vehicle Speed Sensor (VSS)2WD: Protrudes from the transmission
housing, just ahead of the propeller shaft.
4WD: Protrudes from the rear output shaft
housing of the transfer case.
5Heated Oxygen Sensor (Bank 1, HO2S 1)Threaded into the exhaust pipe ahead of the
right-hand catalytic converter
6Heated Oxygen Sensor (Bank 2, HO2S 1)Threaded into the exhaust pipe ahead of the
left-hand catalytic converter
Fuse and Relay Panel (Underhood Electrical Center)
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