Mitsubishi Grandis. Manual - part 296

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-69

Step 5. Check the wiring harness between C-10 
outside/inside air selection damper control motor 
connector terminal No.1 and the ignition switch 
(IG2). 

NOTE: 

Prior to the wiring harness inspection, check joint 
connector C-01 and junction block connectors C-205 
and C-202, and repair if necessary.

• Check the motor power supply 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 6. Check the outside/inside air selection 
damper control motor

Refer to GROUP 55, Resistor, blower motor and 
inside/outside air selection damper control motor 

P.55-208

.

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Replace the outside/inside air selection 
damper control motor.

Step 7. Connector check: C-105 A/C-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the connector.

AC310628AI

Harness side

Connector: C-10 <RHD>

AC310631AE

Connector: C-01 <RHD>

AC310619

Connectors: C-202, C-205 <RHD>

AF

Junction block (Front view)

C-205

C-202

C-205

Harness side

C-202

Harness side

AC310631AC

Connector: C-105 <RHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-70

Step 8. Check the wiring harness between C-105 
A/C-ECU connector (terminals 37 and 38) and 
C-10 outside/inside air selection damper control 
motor connector (terminals 2 and 3).

• Check the motor activating lines for open or short 

circuit.

Q: Is the check result normal?

YES : 

Replace the automatic air conditioner 

control panel (A/C-ECU).

NO : 

Repair the wiring harness.

AC310628AI

Harness side

Connector: C-10 <RHD>

AC310631AC

Connector: C-105 <RHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-71

INSPECTION PROCEDURE 7: The compressor does not work <LHD>

COMMENTS ON TROUBLE SYMPTOM

When the A/C compressor does not work, the A/C 

compressor circuit system or the CAN bus line may 
be defective.

A/C
COMPRESSOR
RELAY

A/C
COMPRESSOR
ASSEMBLY

A/C-ECU

A/C
REFRIGERANT
TEMPERATURE
SWITCH

MAGNETIC
CLUTCH

IGNITION
SWITCH (IG2)

ENGINE-ECU <M/T>
ENGINE-A/T-ECU <A/T>

RELAY
BOX

FUSIBLE
LINK

26

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

A/C Compressor Assembly Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-72

POSSIBLE CAUSES

• Malfunction of A/C compressor

• Malfunction of A/C compressor relay

• Malfunction of A/C pressure sensor

• Damaged harness wires and connectors

• Malfunction of engine-ECU <M/T> or 

engine-A/T-ECU <A/T>

• Malfunction of the A/C-ECU

Step 1. MUT-III CAN bus diagnostics

Use the MUT-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus lines. (Refer to GROUP 
54D 

− Troubleshooting 

P.54D-16

.)

Step 2. 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 3.

NO : 

Refer to diagnosis code chart 

P.55-8

.

Step 3. MUT-III data list

Check that the following service data display 
contents are normal. (Refer to 

P.55-183

.)

• Item 04: Pressure sensor

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Inspection Procedure 18: Refer to A/C 
pressure sensor system 

P.55-142

 <LHD>.

Step 4. Connector check: B-120 A/C compressor 
assembly connector and C-110 engine-ECU 
connector <M/T> or engine-A/T-ECU <A/T>

Q:  Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the connector.

Step 5. Voltage measurement at B-120 A/C 
compressor assembly connector.

(1) Disconnect the connector, and measure at the 

wiring harness side.

AC311219

Connector: B-120 <LHD>

AB

Harness side

B-120 (B)

AC310615

AI

Harness side

Connector: C-110 <LHD>

C-110 (GR)

AC311219

Connector: B-120 <LHD>

AB

Harness side

B-120 (B)