2002 ISUZU AXIOM Air conditioner

1A±2
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Compressor 1A±53. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution 1A±53. . . . . . . . . . . . . . . . . . . .
General Description 1A±53. . . . . . . . . . . . . . . . . . . . . .
Diagnosis 1A±54. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Clutch Assembly (DKV-14G Type) 1A±55
Parts Location View 1A±55. . . . . . . . . . . . . . . . . . . .
Removal 1A±55. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 1A±57. . . . . . . . . . . . . . . . . .
Installation 1A±57. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor Oil 1A±59. . . . . . . . . . . . . . . . . . . . . . . . .
Oil Specification 1A±59. . . . . . . . . . . . . . . . . . . . . . .
Handling of Oil 1A±59. . . . . . . . . . . . . . . . . . . . . . . .
Compressor Oil Check 1A±59. . . . . . . . . . . . . . . . .
Checking and Adjusting Oil Quantity for
Used Compressor 1A±59. . . . . . . . . . . . . . . . . . . . .
Checking and Adjusting for Compressor
Replacement 1A±60. . . . . . . . . . . . . . . . . . . . . . . . .
Contamination of Compressor Oil 1A±60. . . . . . . .
Oil Return Operation 1A±60. . . . . . . . . . . . . . . . . . .
Replacement of Component Parts 1A±60. . . . . . .
Main Data and Specifications 1A±61. . . . . . . . . . . . .
Special Tools 1A±63. . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Air Conditioning System 1A±64. . . . . . . .
General Description 1A±64. . . . . . . . . . . . . . . . . . . . . .
Automatic Air Conditioner Parts
Configuration 1A±64. . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram 1A±65. . . . . . . . . . . . . . . . . . . . . . .
Functions and Features 1A±70. . . . . . . . . . . . . . . .
Automatic Air Conditioner Block Diagram 1A±71.
Control Panel Layout 1A±72. . . . . . . . . . . . . . . . . . .
Air Control Functions 1A±73. . . . . . . . . . . . . . . . . . .
Control Panel Switch Operation 1A±74. . . . . . . . .
Overview of Construction, Movement and
Control of Major Parts of Automatic Air
Conditioner System 1A±77. . . . . . . . . . . . . . . . . . .
Overview of Automatic Control of Automatic
Air Conditioner 1A±81. . . . . . . . . . . . . . . . . . . . . . .
Automatic Air Conditioning System 1A±82. . . . . .
Troubleshooting 1A±86. . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting, Its Overview and
Procedures 1A±86. . . . . . . . . . . . . . . . . . . . . . . . . .
Auto Air Conditioner Control Unit Power
Supply Diagnosis 1A±87. . . . . . . . . . . . . . . . . . . . . Performance and Movement checklist for
Automatic Air Conditioner Related Parts 1A±89.
Troubleshooting With Self-Diagnosis
Function 1A±91. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection By Failed Location 1A±97. . . . . . . . . . . . .
Inspection of the Sensors 1A±97. . . . . . . . . . . . . . .
Inspection of the Intake Actuator System 1A±101.
Inspection of the Mix Actuator System 1A±104. . . .
Inspection of the Mode Actuator System 1A±107. .
Inspection of the Fan Motor System 1A±110. . . . . .
Inspection of the Magnetic Clutch System 1A±115
Individual Inspection 1A±118. . . . . . . . . . . . . . . . . . .
On-Vehicle Service 1A±121. . . . . . . . . . . . . . . . . . . . . .
Power Transistor 1A±121. . . . . . . . . . . . . . . . . . . . . .
Removal 1A±121. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±121. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Heater/Air Conditioner Control
Unit 1A±121. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±121. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±121. . . . . . . . . . . . . . . . . . . . . . . . . . . .
In Car Sensor 1A±122. . . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±122. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±122. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ambient Sensor 1A±122. . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±122. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±122. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sun Sensor 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Duct Sensor 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±123. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode Actuator 1A±124. . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±124. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±124. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mix Actuator 1A±124. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±124. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±124. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intake Actuator 1A±125. . . . . . . . . . . . . . . . . . . . . . . .
Removal 1A±125. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1A±125. . . . . . . . . . . . . . . . . . . . . . . . . . . .

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±33
Leak Check
Inspection of refrigerant leak
Refrigerant leak may cause an adverse effect not only on
the performance and durability of each component of the
air±conditioner, but also on the global atmosphere.
Therefore, it is most important to repair refrigerant leak
when there is any leak found.
Inspection flow of refrigerant leak
StepActionYe sNo
11. Evacuate the refrigerant system.
2. Charge the refrigerant.
Is there any refrigerant leak?
Repair refrigerant
system.
Go to Step 2
21. Operate the compressor for more than 5 minutes to raise the
pressure on the high pressure side.
Is there any refrigerant leak at high pressure components?
Repair refrigerant
system.
Compressor
operation to be
confirmed.
Inspection Steps
Check the components of air±conditioner to see if there
occurs any refrigerant leak along the flow of refrigerant.
NOTE:

To avoid refrigerant leak detection error, avoid
refrigerant vapor and cigarette smoke presence when
performing the inspection. Also, select a location that
is not susceptible to wind, in case refrigerant vapor is
found it will not be blown off.

Inspection should be conducted chiefly on the pipe
connections and sections where a marked oil
contamination is found. When refrigerant is leaking,
oil inside is also leaking at the same time.

It is possible to visually check the leak from inside the
cooling unit. Follow the method below when
performing the inspection. Remove the drain hose or
resistor of the cooling unit, and insert a leak detector
to see if there are signs of leakage.
High Pressure Side
1. Discharger section of compressor.
2. Inlet/outlet section of condenser.
3. Inlet/outlet section of receiver driver.
4. Inlet section of cooling unit.
Low Pressure Side
1. Outlet section of cooling unit.
2. Intake section of compressor.
Major Checking Points of Refrigerant Leak
Compressor

Pipe connection

Sealing section of shaft

Mating section or cylinder
Condenser

Pipe connection

Welds of condenser bodyReceiver driver

Pipe connection

Attaching section of pressure switch

Section around the sight glass
Evaporator unit (cooling unit)

Pipe connections

Connections of expansion valve

Brazed sections of evaporator
NOTE:

The evaporator and expansion valve are contained in
the case. Remove the drain hose or the resistor of the
cooling unit and insert a leak detector when checking
for any leak.
Flexible hose

Pipe connection

Caulking section of the hose

Hose (cracks, pinholes, flaws)
Pipe

Pipe connection

Pipe (cracks, flaws)
Charge valve
NOTE:

The charge valve, which is used to connect the gauge
manifold, is normally provided with a resin cap. When
the valve inside gets deteriorated, refrigerant will leak
out.Leak at Refrigerant Line Connections
1. Check the torque on the refrigerant line fitting and, if
too loose, tighten to the specified torque.

Use two wrenches to prevent twisting and damage
to the line.

Do not over tighten.
2. Perform a leak test on the refrigerant line fitting.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±39
4. Remove serpentine belt.

Move serpentine belt tensioner to loose side using
wrench then remove serpentine belt.
850RY00005
Legend
(1) Auto Tensioner
(2) Idle Pulley
(3) Cooling Fan Pulley
(4) Serpentine Belt
(5) Power Steering Oil Pump
(6) Air Conditioner Compressor
(7) Crankshaft Pulley
(8) Generator
5. Disconnect refrigerant line connector.

When removing the line connector, the connecting
part should immediately be plugged or capped to
prevent foreign matter from being mixed into the
line.
6. Remove compressor.
Installation
1. Install compressor.

Tighten the compressor fixing bolts to the specified
torque.
Torque: 19 Nwm (14 lbwft)
2. Connect refrigerant line connector.

Tighten the refrigerant line connector fixing bolts to
the specified torque.
Torque: 15 Nwm (11 lbwft)

O-rings cannot be reused. Always replace with new
ones.

Be sure to apply new compressor oil to the O-rings
when connecting refrigerant lines.
3. Install serpentine belt.

Move serpentine belt tensioner to loose side using
wrench, then install serpentine belt to normal
position.4. Connect magnetic clutch harness connector.
New Compressor Installation
The new compressor is filled with 150cc (5.0fl.oz.)of
compressor oil and nitrogen gas. When mounting the
compressor on the vehicle, perform the following steps;
1. Gently release nitrogen gas from the new
compressor.

Take care not to let the compressor oil flow out.

Inspect O-rings and replace if necessary.
871RX033
2. Turn the compressor several times by hand and
release the compressor oil in the rotor.
3. When installing on a new system, the compressor
should installed as it is. When installing on a used
system, the compressor should be installed after
adjusting the amount of compressor oil. (Refer to
Compressor in this section)
871RX035

1A±64
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Automatic Air Conditioning System
General Description
Using a variety of sensors, this automatic air conditioner
accurately senses outside air temperature, solar
radiation quantity, evaporator's blowing temperature, and
interior temperature, then enters these data to the
automatic air conditioner control unit (equipped with the
built-in micro-computer). The data provided to the control
unit enables to automatically control blow temperatureand 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-diagnoisis function of the automatic air
conditioner control unit (with the built-in micro-computer)
allows the unit to access and diagnose a failed part easier
and quicker.
Automatic Air Conditioner Parts Configuration
865R200050
Legend
(1) In Car Sensor
(2) Sun Sensor
(3) Ambient Sensor
(4) Intake Actuator
(5) Blower Unit
(6) Max ± High Relay
(7) Display(8) Audio & Switch Assembly
(9) Evaporator Assembly
(10) Duct Sensor
(11) Mix Actuator
(12) Heater Unit
(13) Automatic Air Conditioner Control Unit
(14) Mode Actuator

1A±70
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Functions and Features
Automatic air conditioning control unit
The control unit features a prominent control and display
panel that clearly shows air conditioner operational
settings (delivered air volume, air outlet location,
inside/outside air circulation, and set temperature).
Desired temperature can be set in ±17
C (1
F)
increments. The current setting appears on the digital
display.
Automatic temperature control
Vehicle interior temperature is maintained at the set level.
It is unaffected by changes in vehicle speed, outside air
temperature, and number of passengers.
Maximum cooling and heating
Moving the switch to the 18
C (65
F) position provides
maximum cooling. Moving the switch to the 32
C (90
F)
position provides maximum heating.
Automatic air flow control
Air flow is automatically and precisely regulated in
response to set temperature change and/or changes in
heater unit mixing door aperture.
Automatic air outlet selection
Appropriate air outlets (VENT, BE-LEVEL, FOOT, or
DEF) are selected in response to changes in outlet
temperatures. The mode switch permits manual selection
of the desired air outlet.
Air source (Fresh air intake from outside the
vehicle or recirculation of the air inside the vehicle)
selection
Automatic switching between outside air (FRESH),
recirculated inside air (RECIRC), or a combination of the
two (MIX) occurs in response to changes in outlet
temperatures.The intake switch permits manual
selection of the air source (FRESH or RECIRC). Mixing
of the two sources is not possible during manual
operation. When the defrost mode switch (DEF) is
pressed, the system automatically switches to outside air
intake.
Cooler start-up control
When the vehicle is parked in a hot area for an extended
period of time, the evaporator becomes hot. When the
cooler is turned on, hot air is blown into the vehicle until
the evaporator cools down. The cooler start-up control
prevents blower operation until the evaporator is able to
provide cool air.
Heater start-up control
When the vehicle is parked in a cold area for an extended
period of time, the heater core becomes cold. When the
heater is turned on, cold air is blown into the vehicle until
the heater core heats up. The heater start-up control
prevents blower operation to the air outlets until the
heater core is able to provide warm air. Air is delivered
through the defrost outlets.
Solar radiation offset
The sun sensor uses a photodiode to precisely determine
the amount of solar radiation affecting the vehicle. The
cooler operates in response to this radiation to quickly
correct the vehicle interior temperature.Switch position memory
Current switch positions are stored in memory when the
ignition switch is turned off. When the ignition switch is
turned on again, the switches automatically return to the
position they were in when the ignition switch was turned
off. This simplifies the restarting procedure.
Self-diagnosis function
The self-diagnosis switches on the control panel permit
easy system troubleshooting. Refer to ªSelf-Diagnosisº
later in this Section.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±71
Automatic Air Conditioner Block Diagram
F01R200004

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±75
A
/
C
´
S
w
i
t
c
hWhen the A/C switch is pressed, the LED light goes out and the
compressor turns off. If the switch is pressed again, the LED light
turns on and the compressor begins to operate.
The air conditioner will not operate if the fan switch is off.
During manual DEF or D/F operation, the A/C LED will turn on or off
in response to switch operation. However, the compressor remains
on regardless of switch position.
D
E
F

M
o
d
e

S
w
i
t
c
hWhen the defrost switch (DEF) is pressed, air flows from the de-
froster outlets. The compressor is on and blower speed is automati-
cally controlled. Air intake is from outside the vehicle (FRESH). The
defroster symbol appears on the display.
When the defrost switch (DEF) is pressed again, the unit returns to
the settings in use before the defroster was turned on.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±77
Overview of Construction, Movement
and Control of Major Parts of
Automatic Air Conditioner System
Automatic 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 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 right side of meter cluster.
865R200001
Legend
(1) Meter Cluster
(2) In Car Sensor
Ambient 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
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.
875R200017
Legend
(1) Ambient Sensor
(2) Condenser Assembly
Duct Sensor
The duct sensor is the sensor to detect temperature
change of the side of evaporator blower coming by fresh
recirculation of intake door or ªonº ªoffº 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.
874R200001
Legend
(1) Sensor Part
(2) Duct Sensor Assembly
(3) Evaporator Assembly