ECU ISUZU TROOPER 1998 Service Repair Manual

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THIS MALUAL INCLUDES THE FOLLOWING SECTIONS:
SECTION No. CONTRNTS
8A LIGHTING SYSTEM
8B WIPER / WASHER SYSTEM
8C ENTERTAINMENT
8D WIRING SYSTEM
8E METER AND GAUGE
8F BODY STRUCTURE
8G SEATS
8H SECURITY AND LOCKS
8I SUN ROOF/CONVERTIBLE TOP
8J EXTERIOR / INTERIOR TRIM

ABBREVIATIONS CHARTS
LIST OF AUTOMOTIVE ABBREVIATIONS WHICH MAY BE USED IN THIS MANUAL
A Ð Ampere(s)
ABS Ð Antilock Brake System
A/C Ð Air Conditioning
ACCEL Ð Accelerator
ACC Ð Accessary
Adj Ð Adjust
A/F Ð Air Fuel Ratio
AIR Ð Air Injection Reaction System
ALDL Ð Assembly Line Diagnostic Link
Alt Ð Altitude
AMP Ð Ampere(s)
ANT Ð Antenna
APS Ð Absolute Pressure Sensor
ASM Ð Assembly
A/T Ð Automatic Transmission/Transaxle
ATDC Ð After Top Dead Center
Auth Ð Authority
Auto Ð Automatic
BARO Ð Barometic
Bat Ð Battery
Bat+ Ð Battery Positive Terminal
Bbl Ð Barrel
BCM Ð Body Control Module
BHP Ð Brake Horsepower
BP Ð Back Pressure
BTDC Ð Before Top Dead Center
¡C ÐDegrees Celsius
Cat. Conv. Ð Catalytic Converter
cc Ð Cubic Centimeter
CCC Ð Computer Command Control
CCOT Ð Cycling Clutch Orifice Tube
CCP Ð Controlled Canister Purge
CID Ð Cubic Inch Displacement
CL Ð Closed Loop
CLCC Ð Closed Loop Carburetor Control
CO Ð Carbon Monoxide
Coax Ð Coaxial
Conn Ð Connector
Conv Ð Converter
CP Ð Canister Purge
CPS Ð Central Power Supply
Crank Ð Crankshaft
CTS Ð Coolant Temperature Sensor
Cu.In. Ð Cubic Inch
CV Ð Constant Velocity
Cyl Ð Cylinder(s)
C
3I Ð Computer Controlled Coil Ignition
DBM Ð Dual Bed Monolith
Diff Ð Differential
DIS Ð Direct Ignition System
Dist ÐDistributor
DOHC Ð Double Overhead Camshaft
DVM Ð Digital Voltmeter (10 meg.)
DVOM Ð Digital Volt Ohmmeter
DVDV Ð Differential Vacuum Delay Valve
EAC ÐElectric Air Control
EAS Ð Electric Air Switching
EBCM Ð Electronic Brake Control Module
ECC Ð Electronic Climate Control
ECM Ð Electronic Control Module
ECU Ð Electronic Control Unit
Ð Engine Calibration Unit (PROM)
EECS Ð Evaporative Emission Control System
EFE Ð Early Fuel Evaporation
EFI Ð Electronic Fuel Injection
EGR Ð Exhaust Gas Recirculation
EGR/TVS Ð Exhaust Gas Recirculation/Thermostatic
Vacuum Switch
ELC Ð Electronic Level Control
ESC Ð Electronic Spark Control
EST Ð Electronic Spark Control
ETR Ð Electronically Tuned Receiver
EVRV Ð Electronic Vacuum Regulator Valve (EGR)
Exh Ð Exhaust
¡F Ð Degrees Fahrenheit
FF Ð Front Drive Front Engine
FL Ð Fusible Link
FLW Ð Fusible Link Wire
FRT ÐFront
FWD Ð Front Wheel Drive
4WD Ð Four Wheel Drive
4x4 Ð Four Wheel Drive
4 A/T Ð Four Speed Automatic Transmission/Transaxle
Gal Ð Gallon
Gen Ð Generator
Gov Ð Governor
g Ð Gram
Harn Ð Harness
HC Ð Hydrocarbons
HD ÐHeavy Duty
HEI Ð High Energy Ignition
Hg Ð Mercury
HiAlt Ð High Altitude
HVAC Ð Heater-Vent-Air Conditioning
IAC Ð Idle Air Control
IC Ð Integrated Circuit
ID Ð Identification
Ð Inside Diameter
IDI Ð Integrated Direct Ignition
IGN Ð Ignition
ILC Ð Idle Load Compensator
INJ ÐInjection
IP Ð Instrument Panel
IPC Ð Instrument Panel Cluster
INT Ð Intake
J/B Ð Junction Block
km Ð Kilometers
km/h Ð Kilometer per Hour
kPa Ð KiloPascals
KV Ð Kilovolts (thousands of volts)
KW Ð Kilowatts
0AÐ12 GENERAL INFORMATION

SERVICE INFORMATION 00 Ð 23
AIR CONDITIONING CYCLE TROUBLESHOOTING
No cooling or insuffi-
cient cooling
Insufficient velocity
of cooling air1. Magnetic clutch does not run
2. Compressor is not rotating properly
·Drive belt loosened or broken
·Magnetic clutch face is not
clean and slips
·Incorrect clearance between
magnetic drive plate and pulley
·Compressor oil leaks from shaft
seal or shell
·Compressor seized
3. Insufficient or excessive charge of
refrigerant
4. Leaks in the refrigerant system
5. Condenser clogged or insufficient
radiation
6. Temperature control link unit of the
heater unit defective
7. Unsteady operation due to foreign
substance in expansion valve
8. Poor operation of electronic thermo-
stat
1. Evaporator clogged or frosted
2. Air leaking from cooling unit or air
duct
3. Blower motor does not rotate prop-
erly·Refer to ÒMAGNETIC CLUTCHÓ
troubleshooting
·Adjust the drive belt to the specified
tension or replace the drive belt
·Clean the magnetic clutch face or
replace
·Adjust the clearance (Refer to
Section 1D ÒCOMPRESSOR OVER-
HAULÓ
·Replace the compressor
·Replace the compressor
·Discharge and recover refrigerant.
Recharge to specified amount.
·Check refrigerant system for leaks
and repair as necessary
Discharge and recover refrigerant.
Recharge to specified amount.
·Clean the condenser or replace as
necessary
·Check radiator or condenser fan
function
·Repair the link unit
·Replace the expansion valve
·Check electronic thermostat and
replace as necessary
·Check evaporator core and replace
or clean the core
·Check evaporator and duct connec-
tion, then repair as necessary
·Refer to Section 00 for ÒFAN
CONTROL KNOB (FAN SWITCH)Ó
troubleshooting
* For the execution of the charging and discharging operation in the table above, refer to the ÒRECOVERY,
RECYCLING, EVACUATING AND CHARGINGÓ in section 1B.
TROUBLEPOSSIBLE CAUSECORRECTION

00 Ð 44 SERVICE INFORMATION
FULL HOT SWITCH
21
Temperature
control link
Full hot switch
1) With the temperature control knob set to the full hot
position, check to see visually if the temperature
control link of the heater unit operate correctly and if
the link contacts securely with the full hot switch.
2) Disconnect the full hot switch connector.
3) With the full hot switch contacted, check to see if
there is any continuity between the switch side
connector terminals.
B-49
Terminal
Full No. 1 2
hot switch
FREE
CONTACT

HEATING AND VENTILATION 1A Ð 21
INSTALLATION
To install, follow the removal steps in the reverse order,
noting the following point:
1. Connect each duct and nozzle securely leaving no
clearance between them and making no improper
matching.
REMOVAL
Preparation:
Disconnect the battery ground cable
1. Instrument panel assembly
·Refer to Section 10 ÒBODYÓ for INSTRUMENT
PANEL ASSEMBLY removal procedure.
2. Center ventilation upper duct
3. Side ventilation duct
4. Center ventilation lower duct
5. Driver lap duct
6. Center console
7. Rear heater duct
·Refer to Section 10 ÒBODYÓ for CONSOLES
removal procedure.
8. Cross beam assembly
·Refer to Section 10 ÒBODYÓ for CROSS BEAM
ASSEMBLY removal procedure.
9. Side defroster nozzle
10. Center defroster nozzle

1B Ð 14 AIR CONDITIONING
REPAIR OF REFRIGERANT LEAKS
Refrigerant Line Connections
Install new O-rings, if required. When disconnecting or
connecting lines, use two wrenches to prevent the
connecting portion from twisting or becoming damaged.
When connecting the refrigerant line at the block joint,
securely insert the projecting portion of the joint portion
into the connecting hole on the unit side and secure with a
bolt.O-ring
Block joint
Apply specified compressor oil to the O-rings prior to
connecting.
CAUTION:
Compressor (PAG) oil to be used varies according to
compressor model. Be sure to apply oil specified for the
model of compressor.
O-rings must be closely aligned with raised portion of
refrigerant line.
Correct Incorrect Incorrect
 

1B Ð 36 AIR CONDITIONING
Removal
1. Disconnect the battery ground cable.
2. Discharge and recover refrigerant.
·Refer to Refrigerant Recovery in this section.
3. Remove radiator grille.
4. Remove condenser fan assembly.
·Disconnect the fan motor connector and
remove the 4 fixing bolts.
5. Remove condenser unit net.
·Remove the 4 fixing screws.
6. Remove motor fan.
7. Remove condenser fan motor.
Installation
To install, follow the removal steps in the reverse
order, noting the following point.
1. Route the fan motor harness in its previous
position and fix it securely with clip and bracket.

1BÐ74 AIR CONDITIONING
FUNCTIONS AND FEATURES
¥ Automatic interior temperature control
This function enables to maintain the interior temperature at the level specified from the temperature
control switch despite of changes in factors such as vehicle speeds, outside air temperature and number
of passengers.
¥ Maximum cooling and heating function
You can select FC (Full cool, namely maximum cooling temperature) or FH (Full heat, maximum heating
temperature) from the temperature control lever.
¥ Automatic air flow control
Air flow is automatically and consecutively fine tuned according to the specified interior temperature and
changes in aperture of the heater unit mix door.
¥ Mode (blow port) control
This function automatically selects either one of the VENT, BI-LEVEL, FOOT or DEP mode for the blow
port according to changes of temperature on the blow port. Using the mode switch allows you to select a
desired blow port manually.
¥ Intake (switching between the fresh air intake and circulation of interior air) control
The intake (switching between fresh air intake and circulation of interior air) mode automatically selects
either FRESH (fresh air intake), MIX or RECIRC (interior air circulation) according to changes of the blow
port temperature. Using the intake switch allows you to select a desired intake port manually (in the
manual operation, FRESH and RECIRC modes alone are available). Pressing the DEF (defrost) mode
switch selects the FRESH (fresh air intake).
¥ Cooler start-up timing control
This function is used for maintaining the air flow at "LOW" level until the evaporator is sufficiently cooled
down. It is intended to prevent a large volume of hot air being blowing into inside of a vehicle when the
cooler is turned on in hot summer season.
¥ Heater start-up timing control
This function is used for maintained the air flow at "LOW" level and also for maintaining the defrost
mode until temperature of coolant in the heater core is sufficiently heated. It is intended to prevent a
large volume of cool air being blown into inside of a vehicle when the heater is turned on in cold winter
season.
¥ Solar radiation quantity offset control
The photodiode on the solar radiation sensor determines solar radiation quantity accurately to offset
interior temperature quickly.
¥ Switch position storing function
This function is used for storing switch positions being selected in the immediately preceding operation,
namely the last time the ignition has been turned off. It simplifies the setup procedures when restarting
the system.
¥ Self-diagnosis function
The self-diagnosis function turned on from the panel switch makes your troubleshooting easier (for detail
of this function, refer to the section titled "Self-Diagnosis").

AIR CONDITIONING 1BÐ97
TROUBLESHOOTING WITH SELF-DIAGNOSIS FUNCTION
1. Overview of Self-Diagnosis Function
The self-diagnosis is implemented in 3 steps for each target. For detail of check procedure contained in
each step, refer to the relevant section of "Check Procedure by Failed Location" listed in the Self-
Diagnosis Operation Procedure.
For turning on the self-diagnosis function and switching of the check step, refer to the flow chart given
below. You can reset the self-diagnosis function by turning the ignition switch off or turning the DEF
switch on for 3 seconds.
2. Self-Diagnosis Operation Procedure
While holding both the Auto switch and the DEF switch on the
automatic heater/air conditioner panel, turn the IG off and then
on.

Does the A/C LED flash every 0.5 second interval?
Press the A/C switch once.
(The past trouble
diagnosing function will
be turned on.)

Does the A/C LED flashes every 0.5 seconds?

Does each output equipment functions normally according to
operation of the temperature setting lever?
Press the DEF switch for 3
seconds consecutively or turn on
and off the IG.
Failure on the
output equipment
or the harness.
Preparations
(1) Set the IG to the OFF mode.
(2) Apply 60W bulb light to the sun sensor.
(3) Set the temperature setting lever on the automatic heater/air
conditioner panel to the center position (25C).
(4) Set the fan switch on the same panel to the Auto position.
End of the self-diagnosis.(The current trouble diagnosing function will be turned on
approximately in 10 seconds.)
YESNO
YESNO
NO
YES
Refer to *1.
Refer to *2.

AIR CONDITIONING 1BÐ99
*2. Displaying the Past Trouble Diagnosing Table
The past trouble diagnosis displays only the items on which trouble has recurred 16 times in the past.
If you press the air conditioning switch once while the current trouble diagnosis is taking place, display
of the past trouble diagnosis will appear on the indicator lamp (LED) of the air conditioning switch.
Results of the diagnosis along the following five items are displayed one by one in 0.5 second interval
irrespective of presence or absence of a trouble. A failed item is indicated by flashing of the LED that is
repeated 3 times within 0.5 seconds. You can locate the failed section by counting in what sequence it
has been displayed.
Items for Past Trouble Diagnosis
LED on
LED off Indication for presence of a trouble Indication for normal state
0.5 0.5 0.5
3 second interval
Display pattern
ON
OFFNormal pattern
In car sensor
Ambient sensor
Sun sensor
Duct sensor
Mix actuatorFailed part
F01RX011
F01RY00007
*3. Check of Output Equipment
FAN
MIX
MODE
DOOR
INTAKE
DOOR
SET UP
TEMPERATURE
100
(%)
33.5
F/H
VENT
B/L
FOOT
D/F
DEF
REC
MIX
FRE
F/C 20 21 22 23 24 25 26 27 28 29 30 F/H (%)
F/C
F01RY00001