Mitsubishi Outlander (2003+). Manual - part 558

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-47

STEP 10. Measure the voltage at B-18X 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 13.

NO : 

 Go to Step 11.

STEP 11. Connector check: B-18X A/C 
compressor relay connector

Q:  Is the check result normal?

YES : 

 Go to Step 12.

NO : 

Repair the connector.

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC301541BW

Connector B-18X
(Relay box side)

Front of 
vehicle

1

3

2

4

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-48

STEP 12. Check the wiring harness between 
B-18X A/C compressor relay connector terminal 
No.4 and the battery.

NOTE: 

Prior to the wiring harness inspection, check 
intermediate connector A-14, and repair if necessary.

•

Check the A/C compressor relay power supply 
line for open circuit.

Q: Is the check result normal?

YES : 

Check that the air conditioner works 

normally.

NO : 

Repair the wiring harness. Check that the 
air conditioner works normally.

STEP 13. Connector check: B-18X A/C 
compressor relay connector and B-27 A/C 
compressor connector

Q:  Is the check result normal?

YES : 

Go to Step 14.

NO : 

Repair the connector.

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC301653

9

8

12 13

1

2

14

3

4

10

15

16

5

6

11

17

7

Connector: A-14

A-14(GR)

AB

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC301648

Connector: B-27

Harness side

1

B-27(B)

AB

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-49

STEP 14. Check the wiring harness between 
B-18X A/C compressor relay connector terminal 
No.1 and B-27 A/C compressor connector 
terminal No.1.

•

Check the A/C compressor relay power supply 
line for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 15.

NO : 

Repair the wiring harness.

STEP 15. Connector check: C-139 engine-ECU 
connector and B-18X A/C compressor relay 
connector

•

Check the A/C compressor relay earth line for 
open circuit.

Q:  Is the check result normal?

YES : 

Go to Step 16.

NO : 

Repair the connector.

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC301648

Connector: B-27

Harness side

1

B-27(B)

AB

AC308718

Connector: C-139 <LHD>

AW

Harness side

C-139 (GR)

AC308735

Connector: C-139 <RHD>

BE

Harness side

C-139 (GR)

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-50

STEP 16. Check the wiring harness between 
C-139 engine-ECU connector terminal No.8 and 
B-18X A/C compressor relay connector terminal 
No.2.

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.00-6

).

NO : 

Repair the wiring harness.

STEP 17. Measure the voltage at C-26 A/C-ECU 
connector. 

(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Turn the ignition switch to the "ON" position.
(3) Disconnect engine-ECU connector C-139 and 

earth terminal 8.

AC301483AG

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC308718

Connector: C-139 <LHD>

AW

Harness side

C-139 (GR)

AC308735

Connector: C-139 <RHD>

BE

Harness side

C-139 (GR)

AC308719

Connectors: C-26, C-139 <LHD>

C-139

AO

Harness side

C-139 (GR)

C-26(B)

29

21

35

27

24

323130

22

23

33

25

34

26

36

28

C-26

Harness side

AC308736

Connectors: C-26, C-139 <RHD>

C-139

C-26

AT

Harness side

C-139(GR)

C-26(B)

29

21

35

27

24

323130

22

23

33

25

34

26

36

28

Harness side