relay ISUZU TROOPER 1998 Service Repair Manual

6E±217 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Throttle Body (TB)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the cover of the intercooler.
035RW051
3. Remove the bolts and the left side bracket to the
intercooler.
4. Remove the air duct with bracket from the intercooler.
035RW086
5. Remove the throttle body assembly from the intake
manifold.
6. Disconnect the ITP sensor electrical connector.
Installation Procedure
NOTE: Do not use solvent of any type when you clean the
gasket surfaces on the intake manifold and the throttle
body assembly. The gasket surfaces and the throttle body
assembly may be damaged as a result.
If the throttle body gasket needs to be replaced,
remove any gasket material that may be stuck to the
mating surfaces of the manifold.

Do not leave any scratches in the aluminum casting.
1. Install the throttle body assembly to the intake
manifold and the air duct with bracket between
throttle body and intercooler.
Torque: 20 N´m (14 Ib ft)
035RW086
2. Connect the ITP sensor electrical connector and
throttle motor control connector.
3. Install the bracket to the intercooler.
4. Install the cover of intercooler.
5. Connect the negative battery cable.
Air Conditioning (A/C) Relay
Removal Procedure
1. Remove the fuse and relay box cover from under the
hood.
2. Consult the diagram on the cover to determine which
is the correct relay.
3. Pull the relay straight up and out of the fuse and relay
box.
Installation Procedure
1. Insert the relay into the correct place in the fuse and
relay box with the catch slot facing forward.
2. Press down until the catch engages.

An audible ªclickº will be heard.
3. Install the fuse and relay box cover.
Exhaust Gas Recirculation
(EGR) Vacuum Switch Valve
(VSV)
Removal Procedure
1. Disconnect the negative battery cable.

6E±226
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
0018
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure. The MAP sensor
signal voltage to the ECM varies from below 2 volts at idle
(high vacuum) to above 4 volts.
The MAP sensor is used to determine the following:

Boost pressure for injector control.

Barometric pressure (BARO).
If the ECM detects a voltage that is lower than the
possible range of the MAP sensor, DTC P0107 will be set.
A signal voltage higher than the possible range of the
sensor will set DTC P0108. An intermittent low or high
voltage will set DTC P1107 or DTC P1106, respectively.
The ECM can detect a shifted MAP sensor. The ECM
compares the MAP sensor signal to a calculated MAP
based on throttle position and various engine load factors.
If the ECM detects a MAP signal that varies excessively
above or below the calculated value, DTC P0106 will set.
Engine Control Module (ECM)
The engine control module (ECM) is located in the engine
room.
The ECM constantly observes the information from
various sensors. The ECM controls the systems that
affect vehicle performance. The ECM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Service Engine Soon lamp), and store diagnostic trouble
codes (DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
ECM Function
The ECM supplies 5, 12 and 110 volts to power various
sensors or switches. The power is supplied through
resistances in the ECM which are so high in value that a
test light will not light when connected to the circuit. In
some cases, even an ordinary shop voltmeter will not give
an accurate reading because its resistance is too low.
Therefore, a digital voltmeter with at least 10 megohms
input impedance is required to ensure accurate voltage
readings. The ECM controls output circuits such as theinjectors, glow relays, etc., by controlling the ground or
the power feed circuit through transistors or through
either of the following two devices:

Output Driver Module (ODM)

Quad Driver Module (QDM)
ECM Components
The ECM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The ECM
monitors numerous engine and vehicle functions via
electronic sensors such as the crankshaft position (CKP)
sensor, and vehicle speed sensor (VSS). The ECM also
controls certain engine operations through the following:

Fuel injector control

Rail pressure control
ECM Voltage Description
The ECM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
ECM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter to assure accurate
voltage readings.
The input/output devices in the ECM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The ECM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
ECM Input/Outputs
Inputs ± Operating Conditions Read

Air Conditioning ªONº or ªOFFº

Engine Coolant Temperature

Crankshaft Position

Electronic Ignition

Manifold Absolute Pressure

Battery Voltage

Intake Throttle Position

Vehicle Speed

Fuel Temperature

Oil Temperature

Intake Air Temperature

EGR boost pressure

Oil rail pressure

Camshaft Position

Accelerator position
Outputs ± Systems Controlled

Exhaust Gas Recirculation (EGR)

Injector Control

QWS

6E±229 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Fuse and Relay Panel (Underhood Electrical Center) RHD
035RW109

6E±230
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Fuse and Relay Panel (Underhood Electrical Center) LHD
035RW108

WIPER/WASHER SYSTEM8B–1
WIPER / WASHER SYSTEM
CONTENTS
Service Precaution 8B–2. . . . . . . . . . . . . . . . . . . . . .
Windshield Wiper/Washer System 8B–2. . . . . . . . .
General Description 8B–2. . . . . . . . . . . . . . . . . . . . .
Windshield Wiper And Washer Switch 8B–2. . . . .
Removal and Installation 8B–2. . . . . . . . . . . . . . .
Windshield Wiper Motor 8B–2. . . . . . . . . . . . . . . . . .
Removal 8B–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windshield Washer Motor 8B–3. . . . . . . . . . . . . . . .
Removal 8B–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windshield Wiper Linkage 8B–4. . . . . . . . . . . . . . . .
Windshield Wiper Linkage and
Associated Parts 8B–4. . . . . . . . . . . . . . . . . . . . . .
Removal 8B–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windshield Wiper Arm/Blade 8B–5. . . . . . . . . . . . . .
Removal 8B–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windshield Wiper Blade Rubber 8B–6. . . . . . . . . . .
Removal 8B–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Wiper/Washer System 8B–7. . . . . . . . . . . . . .
General Description 8B–7. . . . . . . . . . . . . . . . . . . . .
Rear Wiper and Washer Switch 8B–7. . . . . . . . . . .
Removal 8B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Wiper Motor 8B–8. . . . . . . . . . . . . . . . . . . . . . .
Removal 8B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . Alarm & Relay Control Unit 8B–9. . . . . . . . . . . . . . .
Removal 8B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Washer Motor 8B–9. . . . . . . . . . . . . . . . . . . . . .
Removal 8B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Wiper Arm/Blade 8B–10. . . . . . . . . . . . . . . . . . .
Removal 8B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Washer Nozzle 8B–10. . . . . . . . . . . . . . . . . . . . .
Removal 8B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Washer Nozzle Angle Adjustment 8B–10. . .
Rear Wiper Blade Rubber 8B–11. . . . . . . . . . . . . . . .
Removal and Installation 8B–11. . . . . . . . . . . . . . .
Headlight Wiper/Washer 8B–11. . . . . . . . . . . . . . . . .
General Description 8B–11. . . . . . . . . . . . . . . . . . . . .
Headlight Wiper and Washer Switch 8B–12. . . . . . .
Removal 8B–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlight Wiper Arm & Blade 8B–13. . . . . . . . . . . . .
Removal 8B–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlight Wiper Motor 8B–13. . . . . . . . . . . . . . . . . . .
Removal 8B–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 8B–13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlight Washer Motor 8B–14. . . . . . . . . . . . . . . . .
Removal and Installation 8B–14. . . . . . . . . . . . . . .
Main Data and Specifications 8B–14. . . . . . . . . . . . .

8B–2WIPER/WASHER SYSTEM
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.
Windshield Wiper/Washer System
General Description
The circuit consists of the starter switch, windshield wiper
& washer switch, windshield wiper motor, windshield
washer motor and windshield intermittent relay.When the wiper & washer switch is turned on with the
starter switch on, the battery voltage is applied to the
wiper motor to activate the wiper.
The washer motor squirts glass cleaning fluid while the
washer switch is being pushed. The intermittent relay is
used to control motion of the wiper.
Windshield Wiper And Washer Switch
Removal and Installation
Refer to the Lighting Switch (Combination Switch) in
Lighting System section.
Windshield Wiper Motor
Removal
1. Disconnect the battery ground cable.
2. Disconnect the connector.
3. Remove 4 mounting bolts.
4. Remove the windshield wiper motor(1).
880RW007
Installation
To install, follow the removal steps in the reverse order.

WIPER/WASHER SYSTEM8B–7
Rear Wiper/Washer System
General Description
The circuit consists of the starter switch, rear wiper &
washer switch, rear wiper motor, rear washer motor and
rear intermittent relay.When the wiper & washer switch is turned on with the
starter switch on, the battery voltage is applied to the
wiper motor to activate the wiper.
The washer motor squirts glass cleaning fluid while the
washer switch is being pushed. The intermittent relay is
used to control motion of the wiper.
Rear Wiper and Washer Switch
Removal
1. Disconnect the battery ground cable.
2. Remove the front console assembly(1).
Refer to the Instrument Panel Assembly in Body
Structure section.
3. Remove the lower cluster assembly(2).
Refer to the Instrument Panel Assembly in Body
Structure section.
4. Remove the instrument panel driver lower cover(3).
Refer to the Instrument Panel Assembly in Body
Structure section.
821RW024
5. Remove the instrument panel cluster assembly(4).
Refer to the Instrument Panel Assembly in Body
Structure section.
6. Disconnect the connector and push the lock from the
back side of the instrument panel cluster assembly to
remove the rear wiper & washer switch(5).
821RW023
Installation
To install, follow the removal steps in the reverse order,
noting the following point:
1. Push the switch with your fingers until it locks
securely.

WIPER/WASHER SYSTEM8B–9
Alarm & Relay Control Unit
Removal
1. Disconnect the battery ground cable.
2. Remove the glove box.
3. Remove the instrument panel passenger lower cover
assembly.
4. Remove the passenger Knee bolster reinforcement
assembly.
5. Remove the fixing bolts, disconnect the connectors
and then remove the alarm & relay control unit (1).
826RW020
Installation
To install, follow the removal steps in the reverse order.
Rear Washer Motor
Removal
1. Disconnect the battery ground cable.
2. Remove the tailgate trim pad(2).
3. Remove two screws, disconnect the connector,
remove the washer hose and then remove the rear
washer tank(3).
4. Pull out the rear washer motor(1) from the washer
tank.
885RS009
Installation
To install, follow the removal steps in the reverse order.

WIRING SYSTEM 8DÐ1
BODY AND ACCESSORIES
WIRING SYSTEM
CONTENTS
Service Precautions . . . . . . . . . . . . . . . . . . . 8DÐ3
General Description . . . . . . . . . . . . . . . . . . . 8DÐ4Notes for Working on Electrical Items . . 8DÐ4
Symbols and Abbreviations . . . . . . . . . . . 8DÐ10
Parts for Electrical Circuit . . . . . . . . . . . . . 8DÐ12
Reading the Circuit Diagram . . . . . . . . . . 8DÐ21
Main Data and Specifications . . . . . . . . . . . 8DÐ24 Fuse, Fusible Link and Circuit Breaker Location . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ24
Relay Location . . . . . . . . . . . . . . . . . . . . . . 8DÐ27
Diode Location . . . . . . . . . . . . . . . . . . . . . . 8DÐ30
Grounding Point . . . . . . . . . . . . . . . . . . . . . 8DÐ33
Cable Harness Routing . . . . . . . . . . . . . . . 8DÐ45
Fuse Block Circuit . . . . . . . . . . . . . . . . . . . . . 8DÐ53 Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ54
Start and Charging . . . . . . . . . . . . . . . . . . . . 8DÐ67 General Description . . . . . . . . . . . . . . . . . . 8DÐ67
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ68
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ70
Powertrain Control Module (PCM) . . . . . . . 8DÐ80 General Description . . . . . . . . . . . . . . . . . . 8DÐ80
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ81
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ93
QOSIII (4JG2) . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ111 General Description . . . . . . . . . . . . . . . . . . 8DÐ111
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ112
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ114
QOS and EGR System (4JG2) . . . . . . . . . . . 8DÐ118 General Description . . . . . . . . . . . . . . . . . . 8DÐ118
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ119
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ122
Headlight and Fog Light . . . . . . . . . . . . . . . . 8DÐ127 General Description . . . . . . . . . . . . . . . . . . 8DÐ127
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ128
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ130
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ134
Rear Foglight . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ150 Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ151
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ152
Headlight Leveling . . . . . . . . . . . . . . . . . . . . 8DÐ153 General Description . . . . . . . . . . . . . . . . . . 8DÐ153
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ154
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ155
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ156
Clearance Light, Taillight and License Plate Light . . . . . . . . . . . . . . . . . . . . 8DÐ159 General Description . . . . . . . . . . . . . . . . . . 8DÐ159
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ160
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ163
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ168
Interior Illumination Light . . . . . . . . . . . . . . 8DÐ180 General Description . . . . . . . . . . . . . . . . . . 8DÐ180
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ181
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ185
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ192
Turn Signal Light and Hazard Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ193
General Description . . . . . . . . . . . . . . . . . . 8DÐ193
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ194
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ197
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ202
Stoplight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ208 General Description . . . . . . . . . . . . . . . . . . 8DÐ208
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ209
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ212
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ216
Backup Light. . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ220 General Description . . . . . . . . . . . . . . . . . . 8DÐ220
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ221
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ223
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ227
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ230 General Description . . . . . . . . . . . . . . . . . . 8DÐ230
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ231
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ232
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ235
Dome Light, Luggage Room Light, Courtesy Light and Map Light . . . . . . . . . . 8DÐ237
General Description . . . . . . . . . . . . . . . . . . 8DÐ237
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ238
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ240
Power Door Lock . . . . . . . . . . . . . . . . . . . . . . 8DÐ244 General Description . . . . . . . . . . . . . . . . . . 8DÐ244
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ245
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ250
Diagnosi s. . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ2 56
Power Window . . . . . . . . . . . . . . . . . . . . . . . 8DÐ261 General Description . . . . . . . . . . . . . . . . . . 8DÐ261
Circuit Diagram. . . . . . . . . . . . . . . . . . . . . . 8DÐ262
Parts Location . . . . . . . . . . . . . . . . . . . . . . . 8DÐ263
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ266
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . 8DÐ272

8DÐ4 WIRING SYSTEM
The chassis electrical system is a 12Ðvolt system with a
negative ground polarity.
Wire size are appropriate to respective circuits, and
classified by color. (The classification of harnesses by
color is shown on the circuit diagram for ease of harness
identification.)
The wire size is determined by load capacity and the
length of wire required.
The vehicle harnesses are: body harness, chassis
harness, engine room harness, instrument harness,
transmission harness, engine ECGI harness, dome light
harness, door harness, rear body harness, tailgate
harness, SRS harness and battery cables.
The harnesses are protected either by tape or corrugated
tube, depending on harness location.
The circuit for each system consists of the power source,
wire, fuse, relay, switch, load parts and ground, all of
which are shown on the circuit diagram.
In this section, each electrical device is classified by
system.
For major parts shown on the circuit based on the circuit
diagram for each system, a summary, diagnosis of
troubles and inspection procedures are detailed.
Notes for Working on Electrical
Items
Disconnecting the Battery Cable
1. All switches should be in the ÒOFFÓ position.
2. Disconnect the battery ground cable (2).
3. Disconnect the battery positive cable (1).
CAUTION: It is important that the battery ground
cable be disconnected first. Disconnecting the
battery positive cable first can result in a short circuit.
Connecting the Battery Cable
Follow the disconnecting procedure in the reverse order.CAUTION: Clean the battery terminal and apply a
light coat of grease to prevent terminal corrosion.
Disconnecting the Connector
Some connectors have a tang lock to hold the connectors
together during vehicle operation.
Some tang locks are released by pulling them towards
you (1).
Other tang locks are released by pressing them forward
(2).
Determine which type of tang lock is on the connector
being handled.
Firmly grasp both sides (male and female) of the
connector (3).
Release the tang lock and carefully pull the two halves of
the connector apart.
Never pull on the wires to separate the connectors (4).
2
1
General Description
1
2
3
4