Isuzu Trooper (2000 year). Manual - part 34

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–105

Performance and Movement checklist for 
Automatic Air Conditioner Related Parts

Start the engine, and when the engine coolant reached
122

°

F check performance and movement of the related

parts according the following checklist.

Performance Check Using the Manual Switch

No

Item

Checking Approach

Acceptance criteria

No.

Item

Condition

Operation

Acceptance criteria

1

Blowing
temperature
(check movement
of air mix door)

Auto switch must be
turned
on(FAN–AUTOMODE
–AUTO)

1. Select FC for the

setup temperature.

2. Select FH for the

setup temperature.

→

 Then, select the

MAX Control.

1. Cold air shall be blown out.
2. Hot air shall be blown out.

2

Airflow
volume(check
movement of the
mode door)

Set temperature to
77

°

F.

1. Turn the fan knob

off.

2. Turn the fan knob

from LOW to HI.

1. The fan shall be stopped, thus

stopping air blow, too.

2. Airflow volume shall change from

LOW to HI.

3

Blowing
temperature(chec
k movement of
the mode door)

Set temperature to
77

°

F.Set the fan knob

to HI.

Push the mode switch
to change the blow
port mode sequentially
from the VENT
through BI-LEVEL,
FOOT up to DEF.

LED corresponding to each mode
shall be turned on and the blow port
mode shall be switched smoothly.

4

The
interior/outside air
switching mode
(check movement
of intake door)

Set temperature to
77

°

F.

Turn the LED off using
the interior/outside air
switch (this introduces
the outside air intake
mode).  Then, the set
fan knob to HI and
press the
interior/outside switch
to turn on the LED.

The LED indication shall be
switched from OFF to ON
accompanying a change in air
blowing sound.

5

Compressor

Set the temperature to
64.4

°

F (FC).  (Outside

air temperature is
32

°

F or above and

interior temperature at
ordinary temperature.)

Push the “OFF”
switch.
1. Push the Auto

switch.

2. Push the Air

Conditioner switch.

1. As the fan knob is set to the Auto

position, the A/C switch LED
shall come on and the
compressor shall be turned on.

2. As the A/C LED comes off, the

compressor shall be turned off.

1A–106 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Check of Auto Function

No

Item

Checking Approach

Acceptance criteria

No.

Item

Condition

Operation

Acceptance criteria

The LED shall come on. 

Cold air shall be blown out.
The following LEDs shall come on:

Select FC for the
temperature.

D

Blow port mode:

D

Intake mode

D

Fan speed:
MAX Hi

D

A/C

1

Auto function

FAN KNOB “AUTO”

MODE SW “AUTO”

Change the
temperature
gradually starting
with 68

°

F up to

86

°

F.

The following phenomena
shall be recognized.

D

Temperature of blown air: Cold air
is changed to hot air.

D

Change in the air flow volume.

D

The blow port mode LED indication
changes in the following sequence:

Select FH for the

Cold air shall be blown out. The
following LEDs shall come on.

Select FH for the
temperature.

D

Blow port mode:

D

Fan speed: Max
Hi.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–107

Troubleshooting With Self-Diagnosis Function

Overview of Self-Diagnosis Function

The self-diagnosis is implemented in 3 steps for each
target.  For detail of check procedure contained in each
step, refer to the relevant section of “Check Procedure by
Failed Location” listed in the Self–Diagnosis Operation
Procedure.

For turning on the self-diagnosis function and switching of
the check step, refer to the flow chart given below.  You
can reset the self–diagnosis function by turning the
ignition switch off or turning the DEF switch on for 5
seconds.

Self-Diagnosis Operation Procedure 

Step

Action

Value(s)

Yes

No

1

1. Set the IG to the OFF position.
2. Apply 60W bulb light to the sun sensor.
3. Set the temperature setting lever on the automatic

heater/air conditioner panel to the center position
(77

°

F).

4. Set the fan switch on the same panel to the Auto

position.

Is the action complete?

—

Go to Step 2

—

2

While pushing both the Auto switch and the DEF switch
on the automatic heater/air conditioner panel, start the
engine.

Is the current trouble diagnosing function turned on
approximately in 10 seconds?

—

Go to Step 3

—

3

Does the A/C LED flash every 0.5 second interval?

—

Go to Step 4

 Refer to *1.

4

Push the A/C switch once.

Does the A/C LED flash every 0.5 second interval?

—

Go to Step 5

 Refer to *2.

5

Refer to *3 chart “Check of Output Equipment”.

Does each output equipment function normally
according to operation of the temperature setting
level?

—

Go to Step 6

Repair or

replace the

output

equipment or

repair the

harness

6

Push the DEF switch for 5 seconds consecutively or
turn on and off the IG.

Is the action complete?

—

Go to Step 1

—

1A–108 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

*

1

Displaying the Current Trouble

Diagnosing Table

Start the engine while holding down both the Auto switch
and the DEF switch on the control panel, and the table will
appear in approximately 10 seconds to the indicator lamp
(LED) of the air conditioning switch. Result of the
diagnosis along the following 9 items will be shown one by

one in 0.5 second interval irrespective of presence or
absence of a trouble for a given item. When the display 9
items is completed, it is repeated with 3 seconds of
interval in between. A failed item is indicated by flashing of
the LED that is repeated 3 times within 0.5 seconds. If a
trouble is indicated, you can locate the failed section by
knowing when in the total sequence it has been
displayed.

F01RX010

Item for Current Trouble Diagnosis

F01RY00008