Mitsubishi Montero (2004+). Manual - part 640

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-49

STEP 23. Check the wiring harness between dual pressure 
switch connector A-22 (terminal 1) and powertrain control 
module connector D-134 (terminal 69).

NOTE: Also check intermediate connectors A-03. If intermedi-
ate connectors A-03 are damaged, repair or replace the con-
nector as described in GROUP 00E, Harness Connector 
Inspection 

P.00E-2

.

Q: Is the wiring harness between dual pressure switch 

connector A-22 (terminal 1) and powertrain control 
module connector D-134 (terminal 69) in good 
condition?
YES : Go to Step 24.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

AC204185

CONNECTORS : A-03, A-22

A-03(B)

A-22(BR)

A-03(B)

AN

A-22(BR)

2 1

6

12

5

3 4

2

1

9 10

8

7

11

HARNESS SIDE

AC204171

CONNECTOR: D-134

HARNESS SIDE

D-134(GR)

D-134(GR)

AE

80

87

73

66

67

65
74

81

75

82

6261

72

68

69

70

71

78

85

77

8483

76

79

86

63

64

8988

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-50

STEP 24. Check A/C-ECU connector D-23 and powertrain 
control module connector D-134 for damage.
Q: Are A/C-ECU connector D-23 and powertrain control 

module connector D-134 in good condition?
YES : Go to Step 25.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

STEP 25. Check the wiring harness between A/C-ECU 
connector D-23 (terminal 7) and powertrain control module 
connector D-134 (terminal 78).

AC204170

CONNECTOR : D-23

D-23(B)

D-23(B)

CP

HARNESS 
SIDE

1

3

4

2

12

1413

11

6

7

8

10 9

18

19

20

16

17

5

15

AC204171

CONNECTOR: D-134

HARNESS SIDE

D-134(GR)

D-134(GR)

AE

80

87

73

66

67

65
74

81

75

82

6261

72

68

69

70

71

78

85

77

8483

76

79

86

63

64

8988

AC204170

CONNECTOR : D-23

D-23(B)

D-23(B)

CP

HARNESS 
SIDE

1

3

4

2

12

1413

11

6

7

8

10 9

18

19

20

16

17

5

15

AC204171

CONNECTOR: D-134

HARNESS SIDE

D-134(GR)

D-134(GR)

AE

80

87

73

66

67

65
74

81

75

82

6261

72

68

69

70

71

78

85

77

8483

76

79

86

63

64

8988

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-51

NOTE: Also check intermediate connector E-111. If intermedi-
ate connector E-111 is damaged, repair or replace the connec-
tor as described in GROUP 00E, Harness Connector 
Inspection 

P.00E-2

.

Q: Is the wiring harness between A/C-ECU connector D-23 

(terminal 7) and powertrain control module connector 
D-134 (terminal 78) in good condition?
YES : Go to Step 26.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

STEP 26. Check A/C-ECU connector D-23 and heater 
blower controller unit connector D-17 for damage.

Q: Are A/C-ECU connector D-23 and heater blower 

controller unit connector D-17 in good condition?
YES : Go to Step 27.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

AC204176

CONNECTOR : E-111

BF

15

4

14

37

36

26 27

12

11

35

34

23 24

3

13

25

9

2

8

32

20 21

6

5

17

29

30

18

1

7

19

31

10

22

33

16

28

38

AC204171

CONNECTOR : D-17

AP

1

2

3

4

HARNESS 
SIDE

AC204170

CONNECTOR : D-23

D-23(B)

D-23(B)

CP

HARNESS 
SIDE

1

3

4

2

12

1413

11

6

7

8

10 9

18

19

20

16

17

5

15

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-52

STEP 27. Check the wiring harness between A/C-ECU 
connector D-23 (terminal 10) and heater blower controller 
unit connector D-17 (terminal 3).
Q: Is the wiring harness between A/C-ECU connector D-23 

(terminal 10) and heater blower controller unit 
connector D-17 (terminal 3) in good condition?
YES : Go to Step 28.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

STEP 28. Check the flexible flat cable (FFC).

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

control panel assembly. Check that the FCC connection is 
contaminated with foreign material or loose (Refer to 

P.55B-142

).

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

YES : Go to Step 29.
NO :  Repair the FFC (Refer to 

P.55B-142

). The 

temperature control should work normally.

AC204171

CONNECTOR : D-17

AP

1

2

3

4

HARNESS 
SIDE

AC204170

CONNECTOR : D-23

D-23(B)

D-23(B)

CP

HARNESS 
SIDE

1

3

4

2

12

1413

11

6

7

8

10 9

18

19

20

16

17

5

15

AC205264AB