Mitsubishi Grandis. Manual - part 310

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-125

NOTE: Prior to the wiring harness inspection, check 
intermediate connector C-128, and repair if 
necessary.

• Check the input line for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness.

STEP 8. 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.

AC310614

AN

Connectors: C-104, C-128 <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

C-104

C-128

C-104

C-128

AC310632AI

Connectors: C-104, C-128 <RHD>

Harness side

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

C-104

C-128

C-104

C-128

AC310649

AB

Connector: E-03 <LHD>             

Harness side

AC310653

AB

Connector: E-03 <RHD>             

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-126

Step 9. Connector check: C-215 rear blower 
motor connector

Q: Is the check result normal?

YES : 

Go to Step 10.

NO : 

Repair the connector.

STEP 10. Check the rear blower relay

 Refer to 

P.55-196

.

Q: Is the check result normal?

YES : 

Refer to Inspection Procedure 22: Rear 

blower motor power supply system 
<LHD>

P.55-152

  or Inspection Procedure 

23: Rear blower motor power supply system 
<RHD>

P.55-160

 .

NO : 

Replace the rear blower relay.

AC310623

Connector: C-215 <LHD>

AH

Junction block side

Junction block (Front view)

AC310618

Connector: C-215 <RHD>

AH

Junction block side

Junction block (Front view)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-127

INSPECTION PROCEDURE 15: Rear blower does not work <vehicles with dual automatic A/C>

REAR
HEATER
CONTROLLER

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 Heater Controller Circuit <L.H.D>

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-128

COMMENTS ON TROUBLE SYMPTOM

If the rear blower motor does not operate, the rear 
blower motor circuit system may be defective.

POSSIBLE CAUSES

• Malfunction of rear blower relay

• Malfunction of rear blower motor

• Malfunction of rear power transistor 

• Malfunction of the A/C-ECU

• Damaged harness wires and connectors

DIAGNOSIS

Step 1. MUT-III diagnosis code

Check whether the air conditioner sets a diagnosis 
code or not.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Refer to diagnosis code chart 

P.55-8

.

REAR
HEATER
CONTROLLER

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 Heater Controller Circuit <R.H.D>