2002 ISUZU AXIOM engine

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±9
Heater Mode Control Link Unit
Disassembled View
860R200002
Legend
(1) Case (Mode Control)
(2) Heater Unit
(3) Mode Sub-lever
(4) Clip(5) Door Lever
(6) Rod
(7) Mode Actuator
(8) Washer and Mode Main Lever
Removal
1. Disconnect the battery ground cable.
2. Drain engine coolant.
3. Discharge and recover refrigerant (with air
conditioning)

Refer to
Refrigerant Recovery in this section.
4. Remove heater unit.

Refer to
Heater Unit in this section.
5. Remove mode actuator.
6. Remove the case (Mode control) from heater unit.
7. Remove washer and the mode main lever.
8. Remove rod.
9. Press the tab of the sub-lever inward, and take out the
sub-lever.
860RS006

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±11
Heater Temperature Control Link Unit
Disassembled View
860R200003
Legend
(1) Case (Temperature control)
(2) Door Lever
(3) Clip
(4) Rod(5) Clip
(6) Sub-lever
(7) Mix Actuator
(8) Heater Unit
Removal
1. Disconnect the battery ground cable.
2. Drain engine coolant.
3. Discharge and recover refrigerant (with air
conditioning).

Refer to
Refrigerant Recovery in this section.
4. Remove heater unit.

Refer to
Heater Unit in this section.
5. Remove mix actuator.
6. Remove the case (Temperature control) from the
heater unit.
7. Remove rod.
8. Remove sub-lever.
9. Pull out the door lever while raising up the catch of the
door lever.
10. Remove clip.
Installation
To install, follow the removal steps in the reverse order,
noting the following points:
1. Apply grease to the 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.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±19
Evaporation
The refrigerant is changed from a liquid to a gas inside the
evaporator. The refrigerant mist that enters the
evaporator vaporizes readily. The liquid refrigerant
removes the required quantity of heat (latent heat of
vaporization) from the air around the evaporator core
cooling fins and rapidly vaporizes. Removing the heat
cools the air, which is then radiated from the fins and
lowers the temperature of the air inside the vehicle.
The refrigerant liquid sent from the expansion valve and
the vaporized refrigerant gas are both present inside the
evaporator as the liquid is converted to gas.
With this change from liquid to gas, the pressure inside
the evaporator must be kept low enough for vaporization
to occur at a lower temperature. Because of that, the
vaporized refrigerant is sucked into the compressor.
Compression
The refrigerant is compressed by the compressor until it is
easily liquefied at normal temperature.
The vaporized refrigerant in the evaporator is sucked into
the compressor. This action maintains the refrigerant
inside the evaporator at a low pressure so that it can
easily vaporize, even at low temperatures close to 0
C
(32
F).
Also, the refrigerant sucked into the compressor is
compressed inside the cylinder to increase the pressure
and temperature to values such that the refrigerant can
easily liquefy at normal ambient temperatures.
Condensation
The refrigerant inside the condenser is cooled by the
outside air and changes from gas to liquid.
The high temperature, high pressure gas coming from the
compressor is cooled and liquefied by the condenser with
outside air and accumulated in the receiver/drier. The
heat radiated to the outside air by the high temperature,
high pressure gas in the compressor is called heat of
condensation. This is the total quantity of heat (heat of
vaporization) the refrigerant removes from the vehicle
interior via the evaporator and the work (calculated as the
quantity of heat) performed for compression.
Expansion
The expansion valve lowers the pressure of the
refrigerant liquid so that it can easily vaporize.
The process of lowering the pressure to encourage
vaporization before the liquefied refrigerant is sent to the
evaporator is called expansion. In addition, the expansion
valve controls the flow rate of the refrigerant liquid while
decreasing the pressure.
That is, the quantity of refrigerant liquid vaporized inside
the evaporator is determined by the quantity of heat which
must be removed at a prescribed vaporization
temperature. It is important that the quantity of refrigerant
be controlled to exactly the right value.
Compressor
The compressor performs two main functions:It compresses low-pressure and low-temperature
refrigerant vapor from the evaporator into high-pressure
and high-temperature refrigerant vapor to the condenser.
It pumps refrigerant and refrigerant oil through the air
conditioning system.
This vehicle is equipped with a five-vane rotary
compressor.
The specified amount of the compressor oil is 150cc
(5.0 fl. oz.).
The oil used in the HFC-134a system compressor differs
from that used in R-12 systems.
Also, compressor oil to be used varies according to the
compressor model. Be sure to avoid mixing two or more
different types of oil.
If the wrong oil is used, lubrication will be poor and the
compressor will seize or malfunction.
The magnetic clutch connector is a waterproof type.
Magnetic Clutch
The compressor is driven by the drive belt from the crank
pulley of the engine. If the compressor is activated each
time the engine is started, this causes too much load to
the engine. The magnetic clutch transmits the power from
the engine to the compressor and activates it when the air
conditioning is ON. Also, it cuts off the power from the
engine to the compressor when the air conditioning is
OFF. Refer to
Compressor in this section for magnetic
clutch repair procedure.
871RX026
Legend
(1) Magnetic Clutch
(2) Magnetic Clutch Connector
(3) Compressor
Condenser
The condenser assembly is located in front of the radiator.
It provides rapid heat transfer from the refrigerant to the
cooling fins.
Also, it functions to cool and liquefy the high-pressure and
high-temperature vapor sent from the compressor by the
radiator fan or outside air.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±25
Checking The Refrigerant System With Manifold Gauge
Since Refrigerant-134a (HFC-134a) is used in the air
conditioning system in this vehicle, be sure to use
manifold gauges, charging hoses and other air
conditioning service tools for HFC-134a when
checking the refrigerant system.
Conditions:

Run the engine at idle

Air conditioning switch is ªONº

Run the blower motor at ªHIGHº position (5 positions)

Temperature control set to ªMAX COLDº (65
F)

Air source selector at ªCIRCº

Open the engine hood

Close all the doors
Normal Pressure:

At ambient temperature: approx. 25±30
C
(77±86
F).

At low-pressure side: approx. 147.1±294.2 kPa
(21.3±42.7 psi).

At high-pressure side: approx. 1372.9±1863.3 kPa
(199.1±270.2 psi).
Refer to the table on the refrigerant pressure-temperature
relationship.
HFC-134a Pressure-Temperature Relationship
PressureTemperature
(kPa)(psi)(
C)(
F)
365.3±20±4.4
679.7±155
10415±1014
14721±523
19628032
25537541
314451050
392571559
471682068
569822577
677983086
78511 43595
91213240104
10591544511 3
121617650122

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±31
Air Conditioning System
Individual Inspection
Triple Pressure Switch (V6, A/T)
1. Disconnect the connector and check for continuity
between pressure switch side connector terminals (1)
and (2).
2. Reconnect the connector to activate the A/C switch,
and check to see if there is continuity between the
chassis side connector terminals (3) and (4) and the
fan operates.
875RY00010
Condenser Fan
1. Disconnect the condenser fan connector.
2. Connect the battery positive terminal to the
condenser fan side connector terminal No.C-16-1
and negative to the No.C-16-2.
3. Check that condenser fan is rotating correctly.
875R200002
General Repair Procedure
Precautions For Replacement or Repair of
Air Conditioning Parts
There are certain procedures, practices and precautions
that should be followed when servicing air conditioning
systems:

Keep your work area clean.

Always wear safety goggles and protective gloves
when working on refrigerant systems.

Beware of the danger of carbon monoxide fumes
caused by running the engine.

Beware of discharged refrigerant in enclosed or
improperly ventilated garages.

Always disconnect the negative battery cable and
discharge and recover the refrigerant whenever
repairing the air conditioning system.

When discharging and recovering the refrigerant, do
not allow refrigerant to discharge too fast; it will draw
compressor oil out of the system.

Keep moisture and contaminants out of the system.
When disconnecting or removing any lines or parts,
use plugs or caps to close the fittings immediately.
Never remove the caps or plugs until the lines or parts
are reconnected or installed.

When disconnecting or reconnecting the lines, use
two wrenches to support the line fitting, to prevent
from twisting or other damage.

Always install new O-rings whenever a connection is
disassembled.

Before connecting any hoses or lines, apply new
specified compressor oil to the O-rings.

When removing and replacing any parts which
require discharging the refrigerant circuit, the
operations described in this section must be
performed in the following sequence:
1. Use the J-39500 (ACR
4: HFC-134a Refrigerant
Recovery / Recycling / Recharging / System) or
equivalent to thoroughly discharge and recover the
refrigerant.
2. Remove and replace the defective part.
3. After evacuation, charge the air conditioning
system and check for leaks.

1A±36
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
3. Connect the low pressure charging hose of the
manifold gauge to the low pressure side service valve
of the vehicle.
4. Connect the high pressure charging hose of the
manifold gauge to the high pressure side service
valve of the vehicle.
901R100021
Legend
(1) Low Side
(2) High Side
(3) Refrigerant Container
(4) Weight Scale
5. Place the refrigerant container(3) up right on a weight
scale(4).
Note the total weight before charging the refrigerant.
a. Open the refrigerant container valve.
b. Open the low side vale on the manifold gauge set.
Refer to the manufacturer's instructions for a
weight scale charging station.
901RS144
6. Perform a system leak test:

Charge the system with approximately 200 g
(0.44 lbs) of HFC-134a.

Make sure the high pressure valve of the manifold
gauge is closed.

Check to ensure that the degree of pressure does
not change.

Check for refrigerant leaks by using a HFC-134a
leak detector.

If a leak occurs, recover the refrigerant. Repair the
leak and start all over again from the first step of
evacuation.
7. If no leaks are found, continue charging refrigerant to
the air conditioning system.

Charge the refrigerant until the scale reading
decreases by the amount of the charge specified.
Specified amount: 700 g (1.54 lbs)

If charging the system becomes difficult:
1. Run the engine at idle and close all the vehicle
doors.
2. Turn A/C switch ªONº.
3. Set the fan switch to its highest position.
4. Set the air source selector lever to ªCIRCº.
5. Slowly open the low side valve on the manifold
gauge set.
WARNING: BE ABSOLUTELY SURE NOT TO OPEN
THE HIGH PRESSURE VALVE OF THE MANIFOLD
GAUGE. SHOULD THE HIGH PRESSURE VALVE BE
OPENED, THE HIGH PRESSURE REFRIGERANT
WOULD FLOW BACKWARD, AND THIS MAY CAUSE
THE REFRIGERANT CONTAINER TO BURST.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±37
8. When finished with the refrigerant charging, close the
low pressure valve of the manifold gauge and
container valve.
9. Check for refrigerant leaks.
Checking The A/C System
1. Run the engine and close all the vehicle doors.
2. Turn A/C switch ªONº, set the fan switch to its highest
position.
3. Set the air source switch to ªCIRCº, set the
temperature switch to the full cool position.
4. Check the high and low pressure of the manifold
gauge.

Immediately after charging refrigerant, both high
and low pressures might be slightly high, but they
settle down to the pressure guidelines shown
below:

The ambient temperature should be between
25±30
C (77±86
F).

The pressure guideline for the high-pressure side is
approximately 1372.9±1863.3 kPa (199.1±270.2
psi).

The pressure guideline for the low-pressure side is
approximately 147.1±294.2 kPa (21.3±42.7 psi).

If an abnormal pressure is found, refer to
Checking
The Refrigerant System With Manifold Gauge in
this section.
5. Put your hand in front of the air outlet and move the
temperature switch of the control panel to different
positions. Check if the outlet temperature changes as
selected by the control switch.

1A±40
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Condenser Assembly
Condenser Assembly and Associated Parts
875R200022
Legend
(1) Refrigerant Line
(2) Pressure Switch Connector
(3) Condenser & Receiver Tank Assembly
(4) Condenser Air Guide
(5) Front Bumper Assembly(6) Engine Hood Front End W/Engine Hood Lock
& Bumper Stay
(7) Front Center Bumper Retainer
(8) Front Side Bumper Retainer (RH)
(9) Head Light (R/LH)
(10) Front Side Turn Signal Light (R/LH)
(11) Horn (R/LH)
Removal
1. Disconnect the battery ground cable.
2. Discharge and recover refrigerant.

Refer to
Refrigerant Recovery in this section.
3. Remove front bumper assembly.

Refer to the
Front Bumper in Body Structure
section.
4. Remove front center bumper retainer.
5. Remove front side bumper retainer (RH).
6. Remove condenser air guide.
7. Remove engine hood front end with engine hood lock
& bumper stay.

Apply setting mark to the engine hood lock fixing
position before removing it.