Mitsubishi Grandis. Manual — part 306

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-109

INSPECTION PROCEDURE 12: The rear window defogger does not work.

CIRCUIT OPERATION

If the rear window defogger does not operate when
the rear window defogger switch is turned on, the
rear window defogger relay system may be
defective.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Malfunction of the rear window defogger relay

• Damaged the wiring harness or connectors

• Malfunction of the rear window defogger

DIAGNOSIS

Step 1. Check the A/C and outside/inside air
selection damper control motor operation.

Q: Do the A/C and outside/inside air selection damper

control motor work normally?

YES :

Go to Step 2.

NO <LHD> :

Refer to Inspection procedure 26

"Malfunction of the A/C-ECU power supply
system <LHD>

P.55-174

."

NO <RHD> :

Refer to Inspection procedure 27

"Malfunction of the A/C-ECU power supply
system <RHD>

P.55-178

."

REAR
WINDOW
DEFOGGER
RELAY

REAR WINDOW
DEFOGGER

A/C-ECU

POWER
SOURCE

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

FUSIBLE
LINK

30

IGNITION
SWITCH (IG2)

Rear Window Defogger Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-110

Step 2. Connector check: C-106 A/C-ECU
connector and G-07 rear window defogger

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the connector.

Step 3. Voltage measurement at G-07 rear
window defogger connector.

(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Turn the ignition switch to the "ON" position.
(3) Disconnect A/C-ECU connector C-105 and earth

terminal 46.

(4) Measure the voltage between terminal 1 and

body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Go to Step 4.

Step 4. Connector check: C-208 rear window
defogger relay connector

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the connector.

AC310613

AB

Connector: C-106 <LHD>

Harness side

AC310631AB

Connectors: C-106 <RHD>

Harness side

AC310222

Connector: G-07

AB

Harness side

G-07 (B)

AC310222

Connector: G-07

AB

Harness side

G-07 (B)

AC310507

Connector G-07
(Harness side)

BA

AC310623

Connector: C-208 <LHD>

AG

3

4

5

1

2

Junction block side

Junction block (Front view)

AC310618

Connector: C-208 <RHD>

AG

3

4

5

1

2

Junction block side

Junction block (Front view)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-111

Step 5. Check the rear window defogger relay
continuity.

Refer to

P.55-196

.

Q: Is the rear window defogger relay in good

condition?

YES :

Go to Step 6.

NO :

Replace the rear window defogger relay.

Step 6. Voltage measurement at C-208 rear
window defogger relay connector.

(1) Remove the relay, and measure at the junction

block side.

(2) Measure the voltage between terminal 5 and

body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Go to Step 7.

AC310623

Connector: C-208 <LHD>

AG

3

4

5

1

2

Junction block side

Junction block (Front view)

AC310618

Connector: C-208 <RHD>

AG

3

4

5

1

2

Junction block side

Junction block (Front view)

AC310507BB

Connector C-208
(Junction block side)

3

4

5

1

2

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-112

Step 7. Check the wiring harness between C-208
rear window defogger relay connector terminal
No.5 and the fusible link (30).

NOTE:

Prior to the wiring harness inspection, check
intermediate connectors C-125, and junction block
connector C-204, and repair if necessary.

• Check the rear window defogger relay power

supply line for open or short 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.

AC310624

Connectors: C-204, C-208 <LHD>

AI

3

4

5

1

2

Junction block side

Junction block (Front view)

C-208

C-204 (B)

C-208

Harness side

C-204

AC310619

Connectors: C-204, C-208 <RHD>

AJ

3

4

5

1

2

Junction block side

Junction block (Front view)

C-208

C-204 (B)

C-208

Harness side

C-204

AC310613

AD

Connector: C-125 <LHD>

AC310628AB

Connector: C-125 <RHD>