Isuzu Trooper (2000 year). Service manual — part 35

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–109

As shown above, display of result along nine items is
repeated with 3-second interval in between.
Note 1: When checking the sun sensor, apply sufficient
light using a 60W bulb. Otherwise, it can be diagnosed as
failed.
Note 2: If the temperature setting lever is set on both ends
(one set to 64.4

°

F, blue scale = Full cool and the other to

87.8

°

F, red scale = Full hot), they can be diagnosed as

failed.
Note 3: Likewise, the fan switch can be diagnosed as
failed if set on both ends.

*

2

Displaying the Past Trouble Diagnosing

Table

The past trouble diagnosis displays only the items on
which trouble has recurred 16 times in the past.
If you press the air conditioning switch once while the
current trouble diagnosis is taking place, display of the

past trouble diagnosis will appear on the indicator lamp
(LED) of the air conditioning switch.
Results of the diagnosis along the following five items are
displayed one by one in 0.5 second interval irrespective of
presence or absence of a trouble. A failed item is
indicated by flashing of the LED that is repeated 3 times
within 0.5 seconds. You can locate the failed section by
counting in what sequence it has been displayed.
Past trouble code can be cleared by disconnecting one of
the following sources for at least thirty (30) seconds.

NOTE: To prevent system damage, the ignition key must
be “OFF” when disconnecting or reconnecting battery
power.

D

The No.16 fuse (Room lamp, Clock)

D

The negative battery cable. (Disconnecting the
negative battery cable will result in the loss of other
on-board memory data, such as preset radio tuning).

F01RX011

F01RY00007

1A–110 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

*

3

Check of Output Equipment

F01RY00004

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–111

Inspection By Failed Location

Inspection of the Sensors

When the self-diagnosis function has determined that
trouble is present on the sensors, check them according
to the following flow chart.

F01RY00005

1A–112 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Chart 1: In Car Sensor

D08RY00174

Step

Action

Value(s)

Yes

No

1

Disconnect the in car sensor connector. (No.I-34)

Is performance of the sensor normal? (Refer to the
later section on “Individual Inspection”)

—

Go to Step 2

Replace the

in car sensor

2

Is there continuity between the harness side connector
No.I33–1 and No.I34–3?

—

Go to Step 4

Go to Step 3

3

Repair an open circuit between terminal No.I33–1 and
No.I34–3.

Is the action complete?

—

Go to Step 2

—

4

Is there continuity between the harness side connector
No.I33–11 and No.I34–4?

—

Go to Step 6

Go to Step 5

5

Replace the auto air conditioner control unit.

Is the action complete?

—

Verify repair

—