coolant temperature ISUZU TROOPER 1995 Workshop Manual

OA-10 GENERAL INFORMATION
ABBREVIATIONS CHARTS
LIST OF AUTOMOTIVE ABBREVIATIONS WHICH MAY BE USED IN THIS MANUAL
A-Ampere(s)
ABS-Anti lock Brake System
AC-Alternating Current
A/C-Air Conditioning
ACCEL-Accelerator
ACC-Accessory
ACL-Air Cleaner
Adj-Adjust
A/F-Air Fuel Ratio
AIR-Secondary Air Injection System
Alt-Altitude
AMP-Ampere(s)
ANT-Antenna
ASM-Assembly
A/T-Automatic Transmission/Transaxle
ATDC-After Top Dead Center
ATF-Automatic Transmission Fluid
Auth -Authority
Auto -Automatic
BARO-Barometric Pressure
Bat -Battery
B+-Battery Positive Voltage
Bbl-Barrel
BHP-Brake Horsepower
BPT-Backpressure Transducer
BTDC-Before Top Dead Center
oc-Degrees Celsius
CAC-Charge Air Cooler
Calif-California
cc-Cubic Centimeter
CID-Cubic Inch Displacement
CKP-Crankshaft Position
CL-Closed Loop
CLCC-Closed Loop Carburetor Control
CMP-Camshaft Position
CO-Carbon Monoxide
Coax-Coaxial
Conn-Connector
Conv -Converter
Crank-Crankshaft
Cu.ln.-Cubic Inch
CV-Constant Velocity
Cyl-Cylinder(s)
Dl -Distributor Ignition
Diff-Differential
Dist-Distributor
DLC-Data Link Connector
DOHC-Double Overhead Camshaft
DTC-Diagnostic Trouble Code
DTM-Diagnostic Test Mode
DTT-Diagnostic Test Terminal
DVM-Digital Voltmeter (10 meg.)
DVOM-Digital Volt Ohmmeter
EBCM-Electronic Brake Control Module
ECM-Engine Control Module
ECT-Engine Coolant Temperature
EEPROM -Electronically Erasable Programmable
Read Only Memory
EGR-Exhaust Gas Recirculation
El-Electronic Ignition
ETR-Electronically Tuned Receiver
EVAP-Evaporation Emission
Exh-Exhaust
°F-Degrees Fahrenheit
Fed -
Federal (All States Except Calif.)
FF-Front Drive Front Engine
FL-Fusible Link
FLW-Fusible Link Wire
FP-Fuel Pump
FRT-Front
ft-Foot
FWD-Front Wheel Drive
4WD-Four Wheel Drive
4 x
4-Four Wheel Drive
4 A/T-Four Speed Automatic Transmission/
Transaxle
Gal-Gallon
GEN-Generator
GND-Ground
Gov-Governor
g-Gram
Harn -Harness
HC-Hydrocarbons
HD-Heavy Duty
Hg-Hydrargyrum (Mercury)
HiAit-High Altitude
H02S - Heated Oxygen Sensor
HVAC-Heater-Vent-Air Conditioning
lAC-Idle Air Control
IAT -Intake Air Temperature
IC-Integrated Circuit
-
Ignition Control
ID-Identification
-Inside Diameter
IGN-Ignition
INJ-Injection
IP-Instrument Panel
IPC-Instrument Panel Cluster
lnt-Intake
ISC-Idle Speed Control
J/B-Junction Block
kg -Kilograms
km-Kilometers
km/h -Kilometer per Hour
kPa-Kilopascals
kV-Kilovolts (thousands of volts)
kW-Kilowatts
KS -Knock Sensor
L-Liter
lb·ft-Foot Pounds
lb·in-Inch Pounds

FLUID LEVEL CHECK
A fluid loss in any system (except windshield
washer) may indicate a problem. Repair the system
at once.
Engine
oil level -Check level and add if
necessary. The best time to check the engine oil
level is
when the oil is warm. After stopping the
engine with the vehicle on a level surface, wait a
few minutes for the oil to drain back to the oil pan.
Pull
out the oil level indicator (dipstick). Wipe it
clean and push the oil level indicator back down all
the
way. Pull out the oil level indicator, keeping the
tip down, and look at the oil level on it.
Add oil, if needed, to keep the oil level above
the
"ADD" mark and between the "ADD" and
"FULL" marks in the operating range area. Avoid
overfilling the engine since this may cause engine
damage. Push
the oil level indicator back down all
the
way after taking the reading.
If you check the oil level when the oil is cold, do
not run the engine first. The cold oil will not drain
back
to the pan fast enough to give a true oil level.
Engine coolant level and condition -Check
engine coolant level in the coolant reservoir and
add engine
coolant if necessary. Inspect the engine
coolant and replace it if dirty or rusty.
Windshield washer fluid level -Check washer
fluid level in reservoir and add if necessary.
Power steering system reservoir level-Check
and keep at
proper level.
Brake master cylinder reservoir level -Check
fluid. Keep fluid at proper level. A low fluid level
can indicate
worn disc brake pads which may need
to be serviced.
Hydraulic clutch system -Check fluid l~vel in
the reservoir.
Add fluid as required.
Battery fluid level -Check fluid level in the
battery.
FLUID LEAK CHECK
Check for fuel, water, oil or other fluid leaks by
looking at the surface beneath the vehicle after it
has been parked for a while. Water dripping from
the air conditioning system after use is normal. If
you notice gasoline fumes or fluid at any time,
locate the source and correct it at once.
ENGINE OIL AND OIL FILTER
REPLACEMENT
Always use API SE, SF, SG, SH or ILSAC GF-1
quality oils of the proper viscosity.
When choosing an oil, consider the range of
temperatures the car will be operated in before the
next oil change. Then, select the recommended oil
viscosity
from the chart (Fig. OB-1).
Always change the oil and the oil filter as soon as
possible after driving in a dust storm.
MAINTENANCE AND LUBRICATION OB-5
ENGINE COOLING SYSTEM INSPECTION
Inspect coolant/anti-freeze. If coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep
coolant at the proper mixture for proper freeze
protection,
corrosion inhibitor level and best engine
operating temperature.
Inspect hoses and replace if
cracked, swollen or deteriorated. Tighten hose
clamps if equipped with screw-type clamps. Clean
outside of radiator and air conditioning condenser.
Wash
filler cap and neck. To help ensure proper
operation, a pressure test of both the cooling
system and cap is also recommended.
EXHAUST SYSTEM INSPECTION
Visually inspect the exhaust pipes, muffler, heat
shields and hangers
for cracks, deterioration, or
damage.
Be alert to any changes in the sound of the exhaust
system
or any smell of fumes. These are signs the
system may be leaking or overheating. Repair the
system at once,
if these conditions exist. (See also
"Engine Exhaust Gas Safety" and "Three Way
Catalytic Converter" in Owner's manual.)
FUEL CAP, FUEL LINES, AND FUEL TANK
INSPECTION
Inspect the fuel tank, the fuel cap and the fuel lines
every
60,000 miles (96,000 km) for damage which
could cause leakage.
Inspect the fuel cap and the gasket for correct sealing
and physical damage. Replace any damaged parts.
DRIVE BELT INSPECTION
Check the belts driving the steering oil pump, the air
conditioning compressor, and the generator
for
cracks, fraying, wear, and correct tension every 30,000
miles (48,000 km). Adjust or replace as necessary.
WHEEL ALIGNMENT, BALANCE AND
TIRES OPERATION
Uneven or abnormal tire wear, or a pull right or left
on a straight and level road may show the need for
a wheel alignment. A vibration of the steering
wheel or seat at normal highway speeds means a
wheel balancing is needed. Check tire pressure
when the tires are "cold" (include the spare).
Maintain pressure as shown in the tire placard,
which is located on the driver's door lock pillar.
STEERING SYSTEM OPERATION
Be alert for any changes in steering action. An
inspection
or service is needed when the steering
wheel is harder
to turn or has too much free play, or
if there are unusual sounds when turning or parking.

1A-2 HEATING AND VENTILATION
GENERAL DESCRIPTION
HEATER
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.
Defroster nozzle
Side
def hose
The air selector 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
"FRESH" for the introduction of the outside air, or
"CIRC" for the circulation of the inside air. When the
lever is set to "FRESH", the outside air is always
taken into the passenger compartment. When
setting the
lever to "CIRC" 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 "FRESH" to
prevent the windshield from clouding.
Upper center vent duct
A/C-Air Conditioning Lower
center vent duct
<
Heater unit
Duct
Fig. 1A-1
Blower
assembly
Evaporator assembly
Control lever assembly
W/0 A/C
/'

1A-6 HEATING AND VENTILATION
DIAGNOSIS
HEATING CYCLE DIAGNOSIS
TROUBLE POSSIBLE CAUSE CORRECTION
No heating or 1. Blower motor does not run, or • Refer to "FAN CONTROL KNOB (FAN
Insufficient heating.
runs inproperly. SWITCH) DIAGNOSIS".
2. Engine coolant temperature is • Check the engine coolant temperature
low. after warming up the engine and check
the thermostat.
Replace as necessary.
3. Insufficient engine coolant. • Add engine coolant as required .
4. Circulation volume of engine • Check if the water hose to the heater
coolant is insufficient. core is clogged, collapsed or twisted.
Repair
or replace as necessary.
• Check water pump function. Repair or
replace as necessary.
5. Heater core clogged or • Clean or replace as necessary.
collapsed.
6. The heater core is not provided • Repair the temperature control link unit
with air sent from the blower or mode doors.
motor.
• Repair or adjust the control cables.
7. Duct connections defective or • Repair or replace as necessary.
unsealing.
Control lever
moves 1. Cable attaching clip is not • Repair.
but
mode door does correct.
not operate. 2. Link unit of heater unit or blower • Repair.
assembly defective.
The
mode door 1. Link unit of heater unit or blower • Repair.
cannot
be sent to the assembly defective.
mode
selected. 2. Control cable is not adjustment. • Adjust.
_______ __... ..... ..._ ____________ (

1••1 REMOVAL
Preparation:
Disconnect the battery ground cable
Drain engine coolant
1. Heaterunit
• Refer to "HEATER UNIT" 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 (Fig. 1A-14).
Fig. 1A-14
5. Heater core (Fig. 1A-15)
Fig. 1A-15
HEATING AND VENTILATION 1A-13
6. Mode door
• Pull out the mode door while raising up the
catch
of the door lever (Fig. 1A-16).
Fig. 1A-16
(b!] INSPECTION
Check for foreign matter in the heater core, stain or
the core fin defacement.
l••liNSTALLATION
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-15
HEATER TEMPERATURE CONTROL LINK UNIT
5
6
/ /
I I
)
1
Removal steps Installation steps 1. Heater unit 2. Case (Temperature control) To install, follow the removal steps in the
reverse order.
3. Rod 4. Sub-lever
5. Door lever 6. Clip
Fig. 1A-19
1••1 REMOVAL
Preparation:
Disconnect the battery ground cable
Drain engine coolant
1. Heater unit
• Refer to "HEATER UNIT" removal procedure
in this section.
2. Case (Temperature control)
• Remove the case (Temperature control) from
the heater unit.
3. Rod
4. Sub-Lever (Fig. 1A-18)
5. Door Lever
• Pull out the door lever while raising up the
catch of the door lever (Fig. 1A-16).
6. Clip
I••! INSTALLATION
To install, follow the removal steps in the reverse
order,
noting the following points:
1~1 1. Apply grease to sub-lever and to the abrasive
surface
of the heater unit.
I L•l 2. After installing the link unit, check to see if the
link unit operates correctly.

18-14 AIR CONDITIONING
MAGNETIC CLUTCH DIAGNOSIS
When the air conditioning switch and the fan
control knob (fan switch) are turned on with the
engine running, current flows through the
thermostat and the compressor relay to activate the
magnetic clutch.
The air conditioning can be stopped by turning off
the air conditioning switch or the fan control knob
(fan switch). However, even when the air
conditioning is in operation, the electronic
thermostat, the pressure switch or the Engine
BATTER y
~
A/C SW.
FAN SW.
FL-1 BOA MAIN -.Y""'
I
RELAY; HEATER&A/C (8-36)
-
·~
~-----;::: -
I ,--<> -v--ro 2
I 6
! -&r ro 1 l ~ .... --~-'---
11-231
r-g-I 4
I~ 0 I 2 1
l __ 9_ OFF -
lli!J
~
r-----3 I
I 1
I 2 -
ELECTRONIC ~ THERMOSTAT
l __ _
C-20 10A Jd.C
RELAY; RESTART
-=-
ECM -Engine Control Module , NC -Air Conditioning
Control Module (ECM) is used to stop the air
conditioning temporarily by turning off the
magnetic clutch in the prearranged conditions to
reduce the engine load which is being caused by
the rise in the engine coolant temperature, and the
acceleration of the vehicle, etc.
For
the inspection of the relays, switches and units
in the flow chart, refer to "INDIVIDUAL
INSPECTION."
,....-1
2 ......_
.....-=.-2
40. r-
1v-
3
......._ =--
~
I ___ j
PRESSURE
SW.
ECMIC91
~
---2 ----l
•o--
1v-
3
-~-@]
~1
L
[ill
I
I RELAY; COMPRESSOR
I
I I ___ j
ECMIA21 ~
:=:>
MAGNETIC
CLUTCH
,.----I In_ r-r
A1 Kl ., .. ...... A& .. A7 AI ld A10 A11A12 .... •• ., .. a1o an 112
'It!
~
~
Fig.1B-11

ENGINE DIAGNOSIS 6-5
ROUGH ENGINE IDLING OR ENGINE STALLING
Condition Possible cause Correction
Trouble in fuel
Idle air control valve defective Replace
injection system
Throttle shutting
off incomplete Correct or replace
Throttle position sensor circuit open
or shorted Correct or replace
Fuel injector circuits open or shorted Correct or replace
Fuel injectors damaged
Replace
Fuel pump relay defective Replace
Manifold Absolute Pressure Sensor
cable Correct or replace
disconnected
or broken
Manifold Absolute Pressure Sensor defective
Replace
Engine Coolant Temperature Sensor cable Correct
or replace
disconnected
or broken
Engine Coolant Temperature Sensor defective
Replace
Intake Air Temperature sensor cable Correct or replace
disconnected
or broken
Intake Air Temperature sensor defective
Replace
Knock Sensor
(KS) circuits open or shorted
Correct or replace
(DOHC only)
KS defective (DOHC only) Replace
KS Module circuits open or ground
Correct or replace
(DOHC only)
KS Module defective (DOHC only) Replace
Vehicle Speed Sensor circuit open or shorted
Correct or replace
Vehicle Speed Sensor defective
Replace
Trouble in emission
Engine Control Module defective
Replace
control system
Exhaust Gas Recirculation
Valve faulty
Replace
Back Pressure Transducer defective
Replace
Vacuum Switch Valve (VSV); EGR circuit
Correct
open
VSV; EGR defective Replace
Canister purge
VSV circuit open
Correct
VSV; canister circuit open
Correct
VSV; canister defective
Replace
Evaporative Emission Canister Purge control
Replace
valve defective
Trouble in ignition system
Refer
to Hard Start
Troubleshooting Guide
Others Engine lacks compression
Refer to Hard Start
Troubleshooting Guide
Valve incorrectly seated
Lap valve
Air Cleaner Filter clogged
Replace filter element
Valve timing incorrect
Readjust
Idle air control valve broken
Replace
Fast
idle solenoid defective
Replace
Positive Crankcase Ventilation valve defective
or Replace
clogged

6-6 ENGINE DIAGNOSIS
ROUGH ENGINE RUNNING
Complaint
Faulty parts Possible cause Correction
Engine misfires Ignition coil
Coil layer shorted Replace
regularly
high-tension Primary lead wire broken leakage due
Correct cables to defective insulator
Spark plugs
Fouling Clean
or install hotter type
plug
Insulator
nose leaking Replace
Fuel
injectors Fuel injector(s) defective Replace
Dropping register defective Replace
Engine Control
Faulty Replace
Module
Engine knocks Spark plugs
Spark plugs running too hot Install colder type spark
regularly
plugs
Engine Control Faulty
Replace
Module
Engine lacks Spark plugs
Fouled Clean
power Multipart Fuel
Fuel injectors defective Replace
Injection Manifold Absolute Pressure (MAP)
Correct or replace system Sensor or Manifold Absolute Pressure
Sensor
circuit defective
Engine
Coolant Temperature Sensor or Correct or replace
Engine Coolant Temperature Sensor
circuit dcefective
Engine
Control Module faulty Replace
Intake
Air Temperature Sensor or Intake
Air Temperature Sensor circuit Correct or replace
defective
Throttle Position Sensor or Throttle Correct or replace
Position Sensor
circuit defective
Knock
Sensor or Knock Sensor circuits Correct or replace
defective (DOHC only)
Knock Sensor Module or Knock Sensor Correct or replace .
Module
circuits defective (DOHC only)
•

ENGINE DIAGNOSIS 6-7
HESITATION
Condition Possible cause Correction
Hesitation on Throttle
Position Sensor adjustment incorrect Replace
throttle
acceleration valve
assembly
Throttle Position Sensor circuit open
or shorted Correct
or replace
Excessive play in accelerator linkage
Adjust or replace
Manifold Absolute
Pressure (MAP) Sensor circuit open or shorted Correct or replace
MAP Sensor defective Replace
Intake Air
Temperature (IAT) Sensor circuit open or shorted Correct or replace
Knock Sensor
(KS) Circuit open or shorted (DOHC only) Correct or replace
KS defective (DOHC only) Replace
KS Module circuits open or shorted (DOHC only) Correct or replace
KS Module defective (DOHC only) Replace
IAT Sensor defective Replace
Hesitation at
Fuel pressure
too low
high speeds
Fuel tank strainer clogged Clean or replace
Fuel pipe clogged
Clean or replace
Fuel filter clogged
Replace
Defective fuel
pump system Check and replace
Fuel Pressure Control Valve leaking Replace
Fuel injector
not working normally
Power supply or ground circuit for Multipart Fuel Injection Check and correct or
System shorted or open
replace
Distributor defective Replace
Cable of Multipart Fuel Injection System disconnected or defective Correct or replace
Engine Control Module defective Replace
Throttle Position Sensor circuit open
or shorted Correct or replace
Throttle Position Sensor defective Replace
Engine Coolant Temperature Sensor circuit open
or shorted Correct or replace
Engine Coolant Temperature Sensor defective Replace
MAP Sensor cable open
or shorted Correct or replace
MAP Sensor defective
Replace
IAT Sensor circuit open or shorted
Correct or replace
IAT Sensor defective Replace
KS Circuit open or shorted (DOHC only)
Correct or replace
KS defective (DOHC only) Replace
KS Module circuit open or shorted (DOHC only) Correct or replace
KS Module defective (DOHC only) Replace
Throttle valve
not wide opened
Check and correct or
replace
Air Cleaner Filter clogged
Replace filter element
Power supply voltage
too low Check and correct or
replace