coolant temperature ISUZU TROOPER 1998 Service Repair Manual

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

00 Ð 16 SERVICE INFORMATION
TROUBLE POSSIBLE CAUSE CORRECTION
HEATING CYCLE TROUBLESHOOTING
No heating or
Insufficient heating.·Refer to ÒFAN CONTROL KNOB (FAN
SWITCH)Ó Troubleshooting.
·Check the engine coolant temperature
after warming up the engine and check
the thermostat. Replace as necessary.
·Add engine coolant as required.
·Check if the water hose to the heater
core is clogged, collapsed or twisted.
Repair or replace as necessary.
·Check water pump function. Repair or
replace as necessary.
·Clean or replace as necessary.
·Repair the temperature control link unit
or mode doors.
·Repair or adjust the control cables.
·Repair or replace as necessary.
·Refer to ÒCERAMIC HEATERÓ
Troubleshooting.
·Repair.
·Repair.
·Repair.
·Adjust. 1. Blower motor does not run, or
runs improperly.
2. Engine coolant temperature is
low.
3. Insufficient engine coolant.
4. Circulation volume of engine
coolant is insufficient.
5. Heater core clogged or
collapsed.
6. The heater core is not provided
with air sent from the blower
motor.
7. Duct connections defective or
unsealing.
8. Ceramic heater defective.
1. Cable attaching clip is not
correct.
2. Link unit of heater unit or
blower assembly defective.
1. Link unit of heater unit or
blower assembly defective
2. Control cable is not adjusted. Control knob moves
but mode door does
not operate.
The mode door
cannot be set to the
mode selected.

00 Ð 20 SERVICE INFORMATION
CERAMIC HEATER
When the fan control knob (fan switch) turns on
with the temperature control knob set to ÒFULL
HOTÓ (full hot switch ÒONÓ), the ceramic heater in
the heater unit turns on and the blow temperature
goes up. When the ceramic heater turns on, FICDstarts to operate at the same time. When either one
of the fan switch, the full hot switch or the thermo
switch (which turns on when the coolant tempera-
ture gets below 80°C (176°F) turns off, the ceramic
heater also turns off.
FL-3
40A
C/HEATER
RELAY;
HEATER A/CECM
(J1-23)
24
13
C-20
10A
A/C
FL-1
80A
MAIN
B-18B-1
B-36
1
3
X-12
2
4
1
3
X-21
2
4
1
2
1
2
4
13
24
1
1
2CERAMIC
HEATER
FAN SW.
B-19
B-48
I-18
B-44
B-49
RELAY;
THERMO
SW
RELAY;
CERAMIC
HEATER
DIODE
FULL HOT
SW.
B-1
B-48
1
21
22112
B-49
I-18
213
5 4612
34
B-36X-12X-21
1234
B-44
(RHD)
B-2(LHD)
B-2
D08RWD66

SERVICE INFORMATION 00 Ð 27
MAGNETIC CLUTCH
When the A/C switch and the fan control knob (fan
switch) are turned on with the engine running,
current flows through the thermostat and the com-
pressor relay to activate the magnetic clutch.
The air conditioning can be stopped by turning off
the A/C switch or the fan control knob (fan switch).
However, even when the air conditioning is in oper-ation, the electronic thermostat, the pressure switch
or the PCM (6VD1/6VE1 Engine) is used to stop the
air conditioning temporarily by turning off the mag-
netic clutch in the prearranged conditions to reduce
the engine load which is being caused by the rise in
the engine coolant temperature, and the accelera-
tion of the vehicle, etc.
123
45 6
RELAY; A/C
B-36C-20
10A
A/C FL-1
80A
MAIN
1
2
B-2
C-25
2
4
X-5
1
3 (3)
(1)
4
13
24
1
A/C SW.
FAN SW.
I-23
PRESSURE
SW.
RELAY;
THERMOSTAT
B-2
X-7 C-25
C-1C-3E-3I-23
BATTERY
X-7
RELAY: A/C
COMPRESSOR
1
E-3
MAGNETIC
CLUTCHMg
OFF
I-18
2
6
1
321123
12
3412
11
213
5 46
I-18
X-5
B-1(LHD) (RHD)
B-1
1
2 34
W/ CONDENSER
FAN
2
4
1
3
C-3PCM (E15)
C-1PCM (B14)
3
1
2
ELECTRONIC
THERMOSTAT
I-42
I-42B-36
Pin number with ( ); RHD
A1 A2 A3 A4 A5 A6 A7 A8 A9A10 A11 A12 A13 A14 A15 A16B1 B2 B3 B4 B5 B6 B7 B8 B9B10 B11 B12 B13 B14 B15 B16E1 E2 E3 E4 E5 E6 E7 E8 E9E10 E11 E12 E13 E14 E15 E16F1 F2 F3 F4 F5 F6 F7 F8 F9F10 F11 F12 F13 F14 F15 F16
6VD1/6VE1 ENGINE
D08RY00295

When the engine warming up, the warmed engine
coolant is sent out into the heater core. The heater
system supplies warm air into the passenger
compartment to warm it up.
Outside air is circulated through the heater core of
the heater unit and then back into the passenger
compartment. By controlling the mixture of outside
air and heater core air, the most comfortable
passenger compartment temperature can be
selected and maintained.
The temperature of warm air sent to the passenger
compartment is controlled by the temperature
control knob. This knob acts to open and close the
air mix door, thus controlling the amount of air
passed through the heater core.The air select knob, with its different modes, also
allows you to select and maintain the most
comfortable passenger compartment temperature.
The air source select lever is used to select either
ÒFRESHÓ for the introduction of the outside air, or
ÒCIRCÓ for the circulation of the inside air. When
the lever is set to ÒFRESHÓ, the outside air is always
taken into the passenger compartment. When
setting the lever to ÒCIRCÓ position, the circulation
of air is restricted only to the inside air with no
introduction of the outside air and the air in the
passenger compartment gets warm quickened.
However, the lever is normally set to ÒFRESHÓ to
prevent the windshield from clouding.
1A Ð 2 HEATING AND VENTILATION
GENERAL DESCRIPTION
HEATER
Side def hose
Vent box
Upper center vent duct
Lower center
vent ductBlower assembly
Control lever assembly Evaporator
assembly W/A/C
W/O A/C
Duct Heater unit
Lap vent nozzle Vent box Side def hoseDefroster nozzle
Rear heater duct
A/C - Air Conditioning This illustration is based on LHD

Full hot switch Ceramic heater Heater unit
HEATING AND VENTILATION 1A Ð 5
CERAMIC HEATER
When the fan control knob (fan switch) turns on with the temperature control knob set to ÒFULL HOTÓ (full
hot switch ÒONÓ), the ceramic heater in the heater unit gets hot, thus causing the heater blow temperature
of diesel vehicle to get high to improve the heating performance (Since the engine coolant temperature of
diesel vehicle is low, its blow temperature is also low.).
Glow plug
Full hot switch
Fan switch
Thermo switch
Less than 80¡C (177.8¡F)
CERAMIC HEATER
ÒONÓCERAMIC HEATER
ÒOFFÓ
OFF
ON
OFF
OFF
OFF
ON
ON
ON
This illustration is based on RHD

HEATING AND VENTILATION 1A Ð 9
REMOVAL
Preparation:
·Disconnect the battery ground cable
·Drain engine coolant
1. Heater Unit
Refer to ÒHEATER UNITÓ removal procedure in this
section.
2. Duct
3. Case (Mode Control)
Do not remove link unit at this step.
4. Case (Temperature Control)
Separate two halves of core case.
Heater core
5. Heater Core
Heater core
6. Mode Door
Pull out the mode door while raising up the catch of
the door lever.
INSTALLATION
To install, follow the removal steps in the reverse order,
noting the following point:
1. Check that each mode door operates properly.

HEATING AND VENTILATION 1A Ð 13
REMOVAL
Preparation:
·Disconnect the battery ground cable
·Drain engine coolant
1. Heater Unit
Refer to ÒHEATER UNITÓ removal procedure in this
section.
2. Case (Temperature Control)
Remove the case (Temperature control) from the
heater unit.
3. Rod
4. Sub-Lever
5. Door Lever
Pull out the door lever while raising up the catch of
the door lever.
6. Clip
INSTALLATION
To install, follow the removal steps in the reverse order,
noting the following points:
1. Apply grease to sub-lever and to the abrasive surface
of the heater unit.
2. After installing the link unit, check to see if the link
unit operates correctly.

1BÐ60 AIR CONDITIONING




















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"650
"$0
'
'"650-0)
*
1
13
10
9
7
6
5
8 11122
4 3
FULL AUTOMATIC AIR CONDITIONING SYSTEM
GENERAL DESCRIPTION
Using a variety of sensors, this full automatic heater and air conditioner accurately senses outside air
temperature, solar radiation quantity, evaporatorÕs blowing temperature, heater core coolant temperature
and interior temperature, then enters these data to the automatic heater/air conditioner control unit
(equipped with the built-in micro-computer). The data provided to the control unit enables to automatically
control blow temperature and blow air quantity, turn on or off the compressor and switch the blow port as
well as switching between the fresh air intake and interior air circulation.
Resetting the automatic function allows you to switch to the manual control mode.
The self-diagnosis function of the automatic heater and air conditioner control unit (with the built-in micro-
computer) allows the unit to access and diagnose a failed part easier and quicker.
Full Automatic Air Conditioner Parts Configuration
865RY0004
Legend
(1) Lower Center Vent Box
(2) Sun Sensor
(3) Mix Actuator
(4) Mode Actuator
(5) Heater Unit
(6) In Car Sensor(7) Pollen Filter
(8) Automatic Air Conditioner Control Unit
(9) Max-High Relay
(10) Blower Unit
(11) Intake Actuator
(12) Duct Sensor
(13) Evaporator Assembly
This illustration is based on RHD

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").