Mitsubishi Outlander (2003+). Manual - part 529

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-11

•

Malfunction of the magnetic clutch

•

Malfunction of the manual air conditioner control 
panel (A/C-ECU)

•

Damaged the wiring harness or connectors

•

Malfunction of the engine-A/T-ECU

DIAGNOSIS

STEP 1. Check the defogger and outside/inside 
air selection damper control motor operation.

Q: Do the defogger and outside/inside air selection 

damper control motor work normally?
YES : 

Go to Step 2.

NO : 

Refer to Inspection procedure 9 
"Malfunction of the A/C-ECU power supply 
system 

P.55A-47

."

STEP 2. Check the blower motor operation.

Q: Does the blower motor work normally?

YES : 

Go to Step 3.

NO : 

Refer to Inspection procedure 4 "Blower fan 
and motor do not turn 

P.55A-29

."

STEP 3. Check the A/C compressor.
Check the A/C compressor for compressor oil leaks.

Q: Is the check result satisfactory?

YES : 

Go to Step 4.

NO : 

Replace the A/C compressor or the 
expansion valve.

STEP 4. Measure the voltage at the B-27 A/C 
compressor 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-134, and 

earth terminal 8. <2000>

AC308688

Connector: B-27 <2000>

Harness side

1

B-27(B)

AB

AC308706

Connector: B-27 
<2400-LHD>

Harness side

1

B-27(B)

AB

AC309474AB

Connector: C-134 <2000>

Harness side

22

9

14

15

2 1

3

16

1918

5 4

17

6

21

7

20

8

25

12

10

23

11

24

26

13

JAE-E

AC309471

22

9

14

15

2 1

3

16

1918

5 4

17

6

21

7

20

8

25

12

10

23

11

24

26

13

JAE-E

AC309471

Connector C-134 
(Harness side)

AB

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-12

(4) Disconnect engine-ECU or engine-A/T-ECU 

connector C-139, and earth terminal 8. <2400>

(5) Measure the voltage between terminal 1 and 

body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

 Go to Step 18.

NO : 

 Go to Step 5.

STEP 5. Check the A/C compressor relay 
continuity.

Refer to 

P.55A-57

.

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

YES : 

Go to Step 6.

NO : 

Replace the A/C compressor relay.

STEP 6. Measure the voltage at B-18X A/C 
compressor relay connector.

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

side.

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

(3) Measure the 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 7.

AC309486

Connector: C-139 <2400-LHD>

AC

Harness side

C-139 (GR)

AC309471

AC309471AC

Connector C-139 
(Harness side)

AC301541BU

Connector B-27
(Harness side)

1

AC309476AB

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC301541BV

Connector B-18X
(Relay box side)

Front of 
vehicle

1

3

2

4

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-13

STEP 7. Connector check: B-18X A/C 
compressor relay connector

Q:  Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the connector.

STEP 8. Check the wiring harness between B-18X 
A/C compressor relay connector terminal No.3 
and the ignition switch (IG2).

AC309476AB

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

AC309476AB

Front of 
vehicle

Relay box side

1

3

2

4

B-18X

-

Connector: B-18X

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-14

NOTE: 

Prior to the wiring harness inspection, check interme-
diate connector C-106, junction block connectors 
C-203 and C-205, 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.00-6

).

NO : 

Repair the wiring harness.

STEP 9. Measure the voltage at B-18X A/C 
compressor relay connector.

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

block side.

(2) Measure the voltage between terminal 4 and 

body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

 Go to Step 12.

NO : 

 Go to Step 10.

AC308718

Connector: C-106

AC

C-106(GR)

<LHD>

AC308721

Connectors: C-203, C-205

AQ

Junction block (Front view)

C-205

Harness side

Harness side

C-205

C-203

C-203

<LHD>

4

6 5

3

2

1

21

7

16 15

17

18

20 19

1

2

3

4

5

6

23 22

24

25

28

26

27

9

8

10

11

14

12

13

AC309476AB

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