Mitsubishi Grandis. Manual - part 297

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-73

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

(3) Disconnect engine-ECU connector or 

engine-A/T-ECU connector C-110 and earth 
terminal 8.

(4) Voltage between terminal 1 and body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

 Go to Step 13.

NO : 

 Go to Step 6.

Step 6. Check the A/C compressor relay 
continuity.

 Refer to GROUP 55, On vehicle service

−power 

relay 

P.55-196

.

Q: Is the A/C compressor relay in good condition?

YES : 

Go to Step 7.

NO : 

Replace the A/C compressor relay.

Step 7. Voltage measurement at B-16X A/C 
compressor relay connector.

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

side.

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

(3) Voltage between terminal 3 and body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

 Go to Step 9.

NO : 

 Go to Step 8.

AC310615

AI

Harness side

Connector: C-110 <LHD>

C-110 (GR)

AC309471

AC309471

Connector C-110 
(Harness side)

AF

AC310507AS

Connector B-120
(Harness side)

1

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC301541HX

Connector B-16X
(Relay box side)

Front of 
vehicle

1

3

2

4

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-74

Step 8. Check the wiring harness between B-16X 
A/C compressor relay connector terminal No.3 
and the ignition switch (IG2).

NOTE: 

Prior to the wiring harness inspection, check junction 
block connectors C-202, C-205, joint connector C-31 
and intermediate connector C-17, and repair if 
necessary.

• Check the A/C compressor relay power supply 

line for open circuit.

Q: Is the check result normal?

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC310615

AJ

Connector: C-17 <LHD>

AC310613

AP

Connector: C-31 <LHD>

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

55-75

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 9. Voltage measurement at B-16X A/C 
compressor relay connector.

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

side.

(2) Voltage between terminal 4 and body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

 Go to Step 11.

NO : 

 Go to Step 10.

Step 10. Check the wiring harness between 
B-16X A/C compressor relay connector terminal 
No.4 and the fusible link (26).

NOTE: 

Prior to the wiring harness inspection, check 
intermediate connector A-16, and repair if necessary.

• Check the A/C compressor relay 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.

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC301541HY

Connector B-16X
(Relay box side)

Front of 
vehicle

1

3

2

4

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC310403

AC

Connector: A-16 <LHD>

A-16 (B)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-76

Step 11. Check the wiring harness between 
B-16X A/C compressor relay connector terminal 
No.2 and C-110 engine-ECU <M/T> or 
engine-A/T-ECU <A/T> connector terminal No.8.

• Check the A/C compressor relay power supply 

line for open circuit.

Q: Is the check result normal?

YES : 

 Go to Step 12.

NO : 

Repair the wiring harness.

Step 12. Check the wiring harness between 
B-16X A/C compressor relay connector terminal 
No.1 and B-120 A/C compressor assembly 
connector terminal No.1.

• Check the A/C compressor 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 13. Check the magnetic clutch operation.

 Refer to 

P.55-219

.

Q: Can the sound of the magnetic clutch (click) be 

heard?

YES : 

Go to Step 14.

NO : 

Replace the compressor magnet clutch. 

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC310615

AI

Harness side

Connector: C-110 <LHD>

C-110 (GR)

AC312170

A/C compressor relay

AC

Front of 
vehicle

Connector: B-16X

Relay box side

AC311219

Connector: B-120 <LHD>

AB

Harness side

B-120 (B)