Mitsubishi Grandis. Manual — part 315

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-145

Step 4. Connector check: C-106 A/C-ECU
connector

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the connector.

Step 5. Check the wiring harness between A-37
A/C pressure sensor connector (terminals 2, 1
and 3) and C-106 A/C-ECU connector (terminals
25, 14 and 1).

NOTE: Prior to the wiring harness inspection, check
intermediate connector C-125, and repair if
necessary.

• Check the input line for open circuit.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the wiring harness.

STEP 6. Recheck the trouble symptom

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 :

Replace the A/C-ECU.

AC310631AB

Connectors: C-106 <RHD>

Harness side

AC310396

Connector: A-37 <RHD>

Harness side

AI

A-37 (B)

AC310631AB

Connectors: C-106 <RHD>

Harness side

AC310628AB

Connector: C-125 <RHD>

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-146

INSPECTION PROCEDURE 20: Rear fan switch system <LHD>

COMMENTS ON TROUBLE SYMPTOM

If a rear fan switch signal is not set to the A/C-ECU,
the rear fan switch or the rear fan switch circuit
system may be defective.

POSSIBLE CAUSES

• Malfunction of the rear fan switch

• Malfunction of the A/C-ECU

• Damaged harness wires and connectors

DIAGNOSIS

Step 1. Connector check: C-19 rear fan switch

Q: Is the check result normal?

IGNITION
SWITCH (IG2)

REAR
FAN
SWITCH

A/C-ECU

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

Rear Fan Switch Circuit

AC310613

AL

Connector: C-19 <LHD>

Harness side

C-19 (GR)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-147

YES :

Go to Step 2.

NO :

Repair the connector.

Step 2. Check the rear fan switch

Refer to

P.55-199

.

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Replace the rear fan switch.

Step 3. Voltage measurement at C-19 rear fan
switch 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 5.

NO :

Go to Step 4.

Step 4. Check the wiring harness between C-19
rear fan switch connector terminal No.1 and the
ignition switch (IG2).

NOTE:

Prior to the wiring harness inspection, check joint
connector C-31 and junction block connector C-205
and C-202, and repair if necessary.

• Check the rear fan switch power supply line for

open circuit.

Q: Is the check result normal?

AC310613

AL

Connector: C-19 <LHD>

Harness side

C-19 (GR)

AC310507

Connector C-19
(Harness side)

BD

AC310614

BE

Connectors: C-19, C-31 <LHD>

C-31

C-19 (GR)

C-31

C-19

Harness side

AC310624

Connectors: C-202, C-205 <LHD>

AF

Junction block (Front view)

C-205

C-202

C-205

Harness side

C-202

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-148

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 5. Connector check: C-104 A/C-ECU
connector.

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the connector.

Step 6. Check the wiring harness between C-19
rear fan switch connector terminal No.2 and
C-104 A/C-ECU connector terminal No.71.

• Check the rear fan switch activating lines for

open or short circuit.

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the wiring harness.

STEP 7. Recheck the trouble symptom

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 :

Replace the A/C-ECU.

AC310613

AK

Connector: C-104 <LHD>

Harness side

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

AC310614

BF

Connectors: C-19, C-104 <LHD>

C-104

C-19 (GR)

C-104

C-19

Harness side

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72