Mitsubishi Montero (2004+). Manual - part 660

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-129

STEP 10. Measure the resistance at A/C-ECU connector 
D-24.
(1) Disconnect A/C-ECU connector D-24, and measure at the 

wiring harness side.

(2) Measure the resistance between terminal 36 and ground.

• The measured value should be 2 ohms or less.

Q: Does the measured resistance value correspond with 

this range?
YES : Go to Step 13.
NO :   Go to Step 11.

STEP 11. Check A/C-ECU connector D-24 for damage.

Q: Is A/C-ECU connector in good condition?

YES : Go to Step 12.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

AC204170

CONNECTOR : D-24

D-24(B)

D-24(B)

CQ

22

23

30

31

25

26

33

34

32

24

28

3635

27

29

21

HARNESS 
SIDE

AC204738

HARNESS SIDE : D-24

DM

22

23

30

31

25

26

33

34

32

24

28

3635

27

29

21

AC204170

CONNECTOR : D-24

D-24(B)

D-24(B)

CQ

22

23

30

31

25

26

33

34

32

24

28

3635

27

29

21

HARNESS 
SIDE

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-130

STEP 12. Check the wiring harness between A/C-ECU 
connector D-24 (terminal 36) and the ground.

NOTE: Also check joint connector (8) connector D-30. If joint 
connector (8) connector D-30 is damaged, repair or replace the 
connector as described in GROUP 00E, Harness Connector 
Inspection 

P.00E-2

.

Q: Is the wiring harness between A/C-ECU connector D-24 

(terminal 36) and the ground in good condition?
YES : Go to Step 13.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

STEP 13. Check the flexible flat cable (FFC).

(1) The FFC is connected to the automatic air conditioning 

control panel assembly. Check that the FFC connection is 
not contaminated with foreign material or is not loose (Refer 
to 

P.55B-142

).

(2) There should be continuity across the FFC terminals.
Q: Is the FFC normal?

YES : Replace the A/C-ECU (Refer to 

P.55B-142

). Check 

that the air conditioning works normally.

NO :  Repair the FFC (Refer to 

P.55B-142

). Check that the 

air conditioning works normally.

AC204188

CONNECTOR : D-24, D-30

D-24(B)

D-24(B)

CP

22

23

30

31

25

26

33

34

32

24

28

3635

27

29

21

HARNESS SIDE

9 10

8

6 7

31 32

30

29

18 19 20 21

5

4

2

1

3

27

26

24

23

25

12 13 14 15 16 17

28

11
22
33

D-30

D-30

AC205264AB

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-131

INSPECTION PROCEDURE 11: The A/C Indicator Flashes.

A/C-ECU

A/C
COMPRESSOR

Lock Sensor Circuit

AC204169

CONNECTOR : B-30

AF

B-30(B)

AC204170

CONNECTORS : D-23, D-24

DV

D-24(B)

D-23(B)

AC204176 BM

CONNECTOR : E-111

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-132

.

TECHNICAL DESCRIPTION (COMMENT)
The lock sensor, which are attached to the air condi-
tioning compressor, and its related components may 
be defective if the A/C indicator flashes.

.

TROUBLESHOOTING HINTS

• Malformation of the lock sensor

• Malformation of the A/C-ECU

• Damaged harness wires or connectors

DIAGNOSIS

Required Special Tool:

• MB991223: Test Harness Set

STEP 1. Check A/C-ECU connector D-23, D-24 and A/C 
compressor connector B-30 for damage.

Q:  Is A/C-ECU connector D-23, D-24 and A/C compressor 

connector B-30 in good condition?
YES : Go to Step 2.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

AC204169

CONNECTOR : B-30

AE

B-30(B)

B-30(B)

2

3

1

HARNESS 
SIDE

AC204188

CONNECTORS : D-23, D-24

D-24(B)

D-24(B)

D-23(B)

D-23(B)

HARNESS SIDE

HARNESS SIDE

BH

22

30 29

21

23

31

25

26

33

34

32

24

28

3635

27

1

3

4

2

12

1413

11

6

7

8

10 9

18

19

20

16

17

5

15