1998 ISUZU TROOPER Intake air température sensor

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

1B Ð 2 AIR CONDITIONING
Full Automatic Air Conditioning System....................................1BÐ 60
General Description.....................................................1BÐ 60
Full Automatic Air Conditioner Part Configuration.........................1BÐ 60
Circuit Diagram......................................................1BÐ 62
Function and Features.................................................1BÐ 74
Full Automatic Air Conditioner Block Diagram.............................1BÐ 75
Air Conditioning Parts.................................................1BÐ 76
Control Panel Layout..................................................1BÐ 80
Air Control Functions.................................................1BÐ 81
Operation and Function of Control Panel Switches.........................1BÐ 82
Overview of Construction, Movement and Control of Major Parts of Full Automatic
Air Conditioner System................................................1BÐ 84
Overview of Automatic Control of Full Automatic Air Conditioner............1BÐ 88
Troubleshooting........................................................1BÐ 92
Troubleshooting, Its Overview and Procedures............................1BÐ 92
Performance and Movement Checklist for Automatic Air Conditioner Related
Parts...............................................................1BÐ 95
Troubleshooting with Self-Diagnosis Function............................1BÐ 97
Inspection by Failed Location.............................................1BÐ100
Inspection of the Sensors..............................................1BÐ100
Inspection of the Intake Actuator System.................................1BÐ104
Inspection of the Mix Actuator System...................................1BÐ107
Inspection of the Mode Actuator System.................................1BÐ110
Inspection of the Fan Motor System.....................................1BÐ113
Inspection of the Magnet Clutch System.................................1BÐ118
Inspection of the Air Conditioner Room Temperature Setup System..........1BÐ123
Individual Inspection..................................................1BÐ124
On-Vehicle Service......................................................1BÐ126
Power Transistor.....................................................1BÐ126
Automatic Air Conditioner Control Unit..................................1BÐ126
In Car Sensor........................................................1BÐ127
Ambient Sensor......................................................1BÐ127
Sun Sensor..........................................................1BÐ128
Electronic Thermostat.................................................1BÐ128
Mode Actuator.......................................................1BÐ129
Mix Actuator.........................................................1BÐ129
Intake Actuator......................................................1BÐ130

1B Ð 6 AIR CONDITIONING
DUAL PRESSURE SWITCH
The dual pressure switch is installed on the upper
part of the receiver/drier, to detect excessively high
pressure (high pressure switch) and prevent
compressor seizure due to the refrigerant leaking
(low pressure switch), switching the compressor
ÒONÓ or ÒOFFÓ as required.
The pressure switch connector is waterproof type.
·Low-pressure control kpa (kgácm
2/ PSI)
Compressor
ON: 205.9 ± 30 (2.1 ± 0.3 / 30 ± 4)
(Except 6VD1 / 6VE1, LHD model)
186 ± 30 (1.9 ± 0.3 / 27 ± 4)
(only for 6VD1 / 6VE1, LHD model)
OFF: 176 ± 20 (1.8 ± 0.2 / 26 ± 3)
·High-pressure control
Compressor
ON: 2354 ± 196 (24.0 ± 2.0 / 341 ± 28)
OFF: 2942 ± 196 (30.0 ± 2.0 / 427 ± 28)
TRIPLE PRESSURE SWITCH
Triple pressure switch is installed atop the receiver/
drier. This switch is constructed with a unitized type
of two switches. One of them is a low and high
pressure switch (Dual pressure switch) to switch
ÒONÓ or ÒOFFÓ the magnetic clutch as a result of
irregularly high-pressure or low-pressure of the
refrigerant. The other one is a medium pressure
switch (Cycling switch) to switch ÒONÓ or ÒOFFÓ
the condenser fan sensing the condenser high side
pressure.·Low-pressure control kpa (kgácm
2/PSI)
Compressor
ON: 186 ± 30 (1.9 ± 0.3 / 27 ± 4)
OFF: 176 ± 20 (1.8 ± 0.2 / 26 ± 3)
·Medium-pressure control
Condenser fan
ON: 1471 ± 98 (15.0 ± 1.0 / 213 ± 14)
OFF: 1079 ± 98 (11.0 ± 1.0 / 156 ± 14)
·High-pressure control
Compressor
ON: 2354 ± 196 (24.0 ± 2.0 / 341 ± 28)
OFF: 2942 ± 196 (30.0 ± 2.0 / 427 ± 28)
EXPANSION VALVE
This expansion valve (1) is internal pressure type
and it is installed at the evaporator intake port.
The expansion valve converts the high pressure
liquid refrigerant sent from the receiver/drier to a
low pressure liquid refrigerant by forcing it through
a tiny port before sending it to the evaporator (2).
This type of expansion valve consists of a
temperature sensor, diaphragm, ball valve, ball
seat, spring adjustment screw, etc.
The temperature sensor contacts the evaporator
outlet pipe, and converts changes in temperature to
pressure. It then transmits these to the top chamber
of the diaphragm.
The refrigerant pressure is transmitted to the
diaphragms bottom chamber through the external
equalizing pressure tube.
The ball valve is connected to the diaphragm. The
opening angle of the expansion valve is determined
by the force acting on the diaphragm and the spring
pressure.
The expansion valve regulates the flow rate of the
refrigerant. Accordingly, when a malfunction occurs
to this expansion valve, both discharge and suction
pressures get low, resulting in insufficient cooling
capacity of the evaporator.
Pressure switch
Receiver/Drier
Triple pressure switch
Condenser fan Condenser
1
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1BÐ60 AIR CONDITIONING




















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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").

AIR CONDITIONING 1BÐ75
FULL AUTO display
INTAKE indication
(LED)
(switching between
fresh and interior air)
MODE indication
(LED) (Blow port)
AC display (LED)
FAN indication (LED)
FAN KNOB
AUTO SET
REC FRESH SWITCH
TEMP LEVER
(temperature control)
MODE SWITCH
(blow port selection)
AC SWITCH
IN CAR SENSOR
AMBIENT SENSOR
SUN SENSOR
DUCT SENSOR
MIX ACTUATOR
POTENTIOMETER
MODE ACTUATOR
POTENTIOMETER
AIR MIX DOOR
MODE DOOR
INTAKE ACTUATOR
RECINTAKE DOOR
FAN MOTORPOWER
TRANSISTOR
AUTOMATIC HEATER/AIR CONDITIONER CONTROL UNIT (with the built-in micro-computer)
MAX HI RELAY
PRESSURE
SWITCHAIR CONDITIONER
THERMO RELAY
COMPRESSOR
SWITCH MAGNET
CLUTCH
PCM
PRESSURE
SWITCHAIR CONDITIONER
THERMO RELAYMAGNET
CLUTCH
(4JX1engine)
MIX FRESH
FULL AUTOMATIC AIR CONDITIONER BLOCK DIAGRAM
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1BÐ84 AIR CONDITIONING
OVERVIEW OF CONSTRUCTION,
MOVEMENT AND CONTROL OF MAJOR
PARTS OF FULL AUTOMATIC AIR
CONDITIONER SYSTEM
Automatic Heater/Air Conditioner Control Unit
Equipped with the built-in micro-computer, this
control unit operates on signals from sensors and
input signals from switches to offer total control of
the blower fan, and actuators used for the mode
door, intake door and air mix door.
Its self-diagnosis function enables quicker access to
a failed part and its more accurate troubleshooting.
In Car Sensor
It is a sensor used for detecting room temperature
of a vehicle. This sensor converts a given room
temperature into a resistance value before entering
the data to the automatic heater/air conditioner
control unit.
This in car sensor unites the power driven aspirator
and the motor fan so that a small amount of room
air may be constantly fed to the sensor.
This sensor is provided on the control panel.
Legend
(1) In Car Sensor
(2) Full Automatic Air Conditioner Control UnitAmbient Sensor
This sensor is used for detecting temperature
outside the vehicle. It converts a given outside air
temperature into a resistance value before entering
the data to the automatic heater/air conditioner
control unit.
Thermal effects from the condenser and radiator
during idling after a run can be measured and offset
the automatic amplifier.
This sensor is provided on the side plate situated at
upper right side of the condenser.
Legend
(1) Ambient Sensor
(2) Condenser Assembly
¥ Duct Sensor
The sensor is the sensor to detect temperature
change of the side of evaporator blower coming
by fresh recirculation of intake door or "on" "off"
of compressor.
The temperature is converted to resistant rate.
And it works as thermostat to control to prevent
freezing of evaporator.
This sensor is installed in the upper case of
evaporator.


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AIR CONDITIONING 1BÐ85
Legend
(1) Duct Sensor
(2) Evaporator Assembly
(3) Amplifierblock
In Car Sensor
It is a photodiode used for detecting quantity of
solar radiation. This sensor converts the offset
signal generated by changes in the interior
temperature (which results from fluctuations in
solar radiation) into photoelectric current to enter
into the automatic heater/air conditioner control
unit.
This sensor is provided at top of the defroster grill.
Legend
(1) Sun SensorActuator
The actuators are power driven type containing a
small motor. Receiving output current from the
automatic heater/air conditioner control unit,
actuators drive the heater and blower unit mode
doors.
Actuators consist of the mode actuator used for
switching the mode (blow port selection), the mix
actuator used for changing aperture of the air mix
door, the intake actuator used for switching the
intake mode(fresh air/interior air).
Legend
(1) Mix Actuator
(2) Heater Unit
(3) Mode Actuator
(4) Blower Unit
(5) Intake Actuator
The actuator changes the motor speed using the
gear and drives each door rotating the output axis
united with the sliding contact.
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This illustration is based on RHD
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This illustration is based on RHD