2002 ISUZU AXIOM display

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.

1A±74
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Control Panel Switch Operation
Switch NamePanel DisplaySwitch Operation
A
u
t
o

S
w
i
t
c
hDuring manual outside air intake (FRESH), pressing the AUTO
switch cancels manual outside air intake. The display panel shows
the current set temperature, the current air outlet(s), and the blower
speed. The intake switch LED shows the current air source. The
A/C switch LED is on.
Air volume, air outlet operation, and air source are controlled
automatically. The compressor is on.
During manual inside air recirculation (REC), pressing the AUTO
switch does not cancel inside air recirculation. The intake switch
LED is on.
O
f
f

S
w
i
t
c
hWhen the OFF switch is pressed, the display panel clears except
for the air outlet indication. Blower and compressor operation stop.
The air source switches from automatic to outside air.
During manual inside air recirculation (REC), pressing the OFF
switch does not cancel inside air recirculation. The intake switch
LED is on.
F
a
n

´


S
w
i
t
c
h
When the fan switch is pressed, air outlet volume (fan speed) can
be manually controlled. Other control switches are unaffected. The
display panel clears AUTO indication.
1. FAN switch is pressed during automatic fan control (AUTO)
Fan control (AUTO)"Press  fan switch"Fan speed increases
from automatic set speed to HI
Fan control (AUTO)"Press
fan switch"Fan speed decreases
from automatic set speed to LO
2. Fan switch is pressed when the fan is off.
Fan (OFF)"Press  fan switch"The fan operates at LO speed
Fan (OFF)"Press
fan switch"The fan operates at LO speed
3. Fan switch is pressed when the fan is in manual operation.
Manual (LO)"Press  fan switch"Manual operation
(LO)" (M1)"(M2)"(M3)"(HI)
Manual (HI)"Press
fan switch"Manual operation
(HI)"(M3)"(M2)"(M1)"(LO)
M
o
d
e

S
w
i
t
c
hPress the mode switch to manually select the air outlet(s). Each
time the switch is pressed, the air outlets change in the progression
shown below.
Mode switch (Automatic control of air
outlets)"VENT"BI-LEVEL"FOOT"DEF/FOOT

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.

1A±76
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
I
Pressing the intake switch permits manual control of air intake and/
or recirculation.
I
n
t
a
k
e

S
w
i
t
c
h
If the intake switch is pressed during manual DEF or D/F, the intake
switch LED briefly turns on. However, outside air intake (FRESH)
continues.
T
e
m
p
e
r
a
t
u
r
e

C
o
n
t
r
o
l
S
w
i
t
c
hThe display panel temperature setting can be set from 18
C (65
F)
to 32
C (90
F).
Pressing and immediately releasing the  switch increases the
temperature setting in -17
C (1
F) increments. If the switch is
pressed and held, the temperature setting increases rapidly.
Pressing and immediately releasing the
switch decreases the
temperature setting in -17
C (1
F) decrements. If the switch is
pressed and held, the temperature setting decreases rapidly.
When the temperature setting is at 32
C (90
F), the unit is set to
maximum heat mode.
When the temperature setting is at 18
C (65
F), the unit is set to
maximum cooling mode.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±89
Performance and Movement
checklist for Automatic Air
Conditioner Related Parts
Start the engine, and when the engine coolant reached
50
C (122
F) check performance and movement of the
related parts according the following checklist.
Performance Check Using the Manual Switch
NoItemProcedureCriteriaNo.ItemConditionOperationCriteria
1
Air discharge
temperature
(Ai i d
Auto±switch ONSet temperature to
18
C (65
F).Cold air discharge.
1(Air±mix door
operation)Set temperature to
32
C (90
F).Hot air discharge.
2
Air discharge
volume (Fan
operation)Fan switch ON1. Set temperature to
25
C (77
F).
2. Press the OFF
switch.Fan does not operate. There is no
air discharge.
21. Set temperature to
25
C (77
F).
2. Press the fan 
switch.Fan operates. Fan speed increases
each time the switch is pressed (LO
to HI in 5 increments).
3
Air discharge
temperature
(Mode door
operation)Fan in manual
5±speed operation1. Set temperature to
25
C (77
F).
2. Press the mode
switch.
3. Move through the 5
modes
(VENT"BI±LEVEL
"FOOT"DEF/FO
OT"DEF).
Panel display lights for each
mode.

Air discharge outlet position
changes for each mode.
4
Inside/outside air
mode (Intake door
operation)Auto±switch ON1. Set temperature to
25
C (77
F).
2. Press the intake
switch.
3. Press the fan 
switch.
4. Set the fan to the
highest speed.
5. Press the intake
switch.
Intake switch LED turns from on
to off.

Air discharge sound changes.
5
CompressorOutside air
temperature above
0
C (32
F) and
vehicle interior at
normal temperature1. Set temperature to
25
C (77
F).
2. Press the OFF
switch.
3. Press the
auto±switch.
4. Press the air
conditioner switch.
When the auto±switch is
pressed, the LED in the air
conditioner switch turns on and
the compressor begins
operation.

When the air conditioner switch
is pressed, the LED in the air
conditioner switch turns off and
the compressor stops operation.

1A±90
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Check of Auto Function
NoItemProcedureCriteriaNo.ItemConditionOperationCriteria

AUTO display highlighted on
display panel.

Cold air discharge.
Set temperature to
18
C (65
F)

VENT mode.
18C (65F).
Intake switch LED on.

Fan speed bar graph display at
MAX6dash;HI

A/C switch LED on.
1Automatic operationAuto-switch ON
Gradually increase
the temperature
setting from 18
C
(65
F) to 31.5
C
(89
F).

Temperature of air discharge
increases with increase in setting
temperature.

Air discharge volume changes.

Panel display shows VENT,
BI±LEVEL, FOOT, or DEF/FOOT.

Hot air discharge.

A/C bar graph display disappears.
Set temperature to
32
C (90
F)

Foot mode.
32
C (90
F).
Intake LED switch off.

Fan speed bar graph display at
MAX-HI

A/C switch LED on.

1A±92
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
StepActionValue(s)Ye sNo
11. Allow the engine to idle until it completely warms up.
2. Turn the starter switch to the OFF position.
3. Place a 60±watt lamp approximately 15 cm from the
sun sensor.
NOTE: This procedure is best performed at night or in
a dark, unlit area.
Is the action complete?
ÐGo to Step 2Ð
2Simultaneously press and hold the RESET key and the
CLOCK key (display unit).
Move the starter switch to start the engine.
Does DIAG appear on the display?
ÐGo to Step 3
Replace
display unit
3Press the COMPUTER MODE key.
Does DIAG AIRCON appear on the display?
ÐGo to Step 4
Replace
audio unit
4NOTE: A '1' should appear in the set temperature
segment of the display.
Does '0' appear in the outside air segment of the
display?
ÐGo to Step 6Go to Step 5
5Repair or replace damaged parts.
NOTE: Refer to
Step 1 Trouble Code Table.
Is the action complete?ÐGo to Step 1Ð
6Press and release the  fan switch (one time only).
NOTE: A '2' should appear in the set temperature
segment of the display.
Does '0' appear in the outside air segment of the
display?
ÐGo to Step 8Go to Step 7
7Repair or replace damaged parts.
NOTE: Refer to
Step 2 Trouble Code Table.
Is the action complete?ÐGo to Step 1Ð
8Press and release the  fan switch (one time only).
NOTE:

Refer to
Step 3 Sensor Output Check for a sample
output value.

A '3' should appear in the set temperature
segment of the display.
Does the correct sensor output value appear in the
outside air segment of the display?
ÐGo to Step 10Go to Step 9
9Repair or replace damaged parts.
NOTE: Refer to
Trouble Spot Inspection.
Is the action complete?ÐGo to Step 1Ð
10Press and release the  fan switch one time only.
NOTE: Refer to
Step 4 (Operation Check) for display
readings and inspection steps.
Are all parts operating normally?
ÐGo to Step 12Go to Step 11