Mitsubishi Grandis. Manual — part 294

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-61

Step 6. Check the wiring harness between C-12
front power transistor connector terminal No.2
and body earth.

• Check the blower linear controller earth line for

open circuit.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00, How to
Cope with Intermittent Malfunction

P.00-5

.)

NO :

Repair the wiring harness.

Step 7. Connector check: C-106 A/C-ECU
controller connector

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Repair the connector.

AC310615

AG

Connector: C-12 <LHD>

Harness side

AC310628AG

Connector: C-12 <RHD>

Harness side

AC310613

AB

Connector: C-106 <LHD>

Harness side

AC310631AB

Connectors: C-106 <RHD>

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-62

Step 8. Check the wiring harness between C-106
A/C-ECU connector (terminals 2 and 3) and C-12
front power transistor controller connector
(terminals 3 and 1).

• Check the blower linear controller power supply

line for open circuit.

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Repair the wiring harness.

Step 9. Replace the front power transistor and
check the trouble symptom

Check that the front blower motor operates normally.

Q: Does the blower motor work normally?

YES :

This diagnosis is complete.

NO :

Replace the automatic air conditioner
control panel (A/C-ECU)

STEP 10. Check the trouble symptom

Check that the front blower motor operates normally.

Q: Is the check result normal?

YES :

This diagnosis is complete.

NO :

Replace the A/C-ECU.

AC310615

AG

Connector: C-12 <LHD>

Harness side

AC310628AG

Connector: C-12 <RHD>

Harness side

AC310613

AB

Connector: C-106 <LHD>

Harness side

AC310631AB

Connectors: C-106 <RHD>

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-63

INSPECTION PROCEDURE 5: The inside/outside air changeover is impossible. <LHD>

COMMENTS ON TROUBLE SYMPTOM

When inside air cannot be changed to outside air
vice versa even if its changeover switch is on, the
outside/inside air selection damper control motor
system may be defective.

POSSIBLE CAUSES

• Malfunction of the outside/inside air selection

damper control motor

• Damaged the wiring harness or connectors

• Malfunction of the automatic air conditioner

control panel (A/C-ECU)

DIAGNOSIS

STEP 1. Check the operation of the heater control
panel

Check that the A/C switch, rear window defogger
switch and air volume control dial can operate.

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

INSPECTION PROCEDURE 26: Refer to
A/C-ECU power supply system
<LHD>

P.55-174

.

Step 2. MUT-III actuator test

Carry out the actuator test. (Refer to

P.55-186

.)

• Item 30: In/out changeover dumper: Recirc

• Item 31: In/out changeover dumper: Fresh

Q: Does the blower motor work normally?

YES :

Replace the automatic air conditioner

control panel (A/C-ECU)

NO :

Go to Step 3.

A/C-ECU

IGNITION
SWITCH (IG2)

OUTSIDE/INSIDE AIR
SELECTION DAMPER
CONTROL MOTOR

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet

Outside/Inside Air Selection Damper Control Motor Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-64

Step 3. Connector check: C-10 outside/inside air
selection damper control motor connector

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Repair the connector.

Step 4. Voltage measurement at C-10
outside/inside air selection damper control motor
connector.

(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Turn the ignition switch to the ON position.

(3) Measure the voltage between terminal 1 and

body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Go to Step 5.

AC310615

AH

Harness side

Connector: C-10 <LHD>

AC310615

AH

Harness side

Connector: C-10 <LHD>

AC310507AR

Connector C-10
(Harness side)