Mitsubishi Montero (2004+). Manual - part 603

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-55

STEP 3. Check rear A/C control unit connector E-20 and 
rear fan control switch connector E-12 for damage.

Q: Is rear A/C control unit connector E-20 and rear fan 

control switch connector E-12 in good condition?
YES : Go to Step 4.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

STEP 4. Check the wiring harness between rear A/C 
control unit connector E-20 (terminal 13) and rear fan 

control switch connector E-12 (terminal 1).

AC204194

CONNECTORS : E-12, E-20

AS

E-20

E-12

E-12

HARNESS SIDE

1
4

2

3

5

6

E-20 <VEHICLES WITH REAR A/C>

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

AC204194

CONNECTORS : E-06, E-12, E-20

AP

E-06

E-06

E-20

E-12

E-12

HARNESS SIDE

1
4

2

3

5

6

E-20 <VEHICLES WITH REAR A/C>

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

22

2021

10

9

8

1718

6 7

19

1415

4 5

1112

1 2 3

13

16

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-56

NOTE: Also check intermediate connector E-06. If intermediate 
connector E-06 is damaged, repair or replace the connector as 
described in GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between rear A/C control unit 

connector E-20 (terminal 13) and rear fan control switch 
connector E-12 (terminal 1) in good condition?
YES : Check that the rear air conditioning works normally.
NO :  Repair the wiring harness. Check that the rear air 

conditioning works normally.

STEP 5. Check rear A/C control unit connector E-20 and 
rear A/C switch E-22 for damage.

Q: Is rear A/C control unit connector E-20 and rear A/C 

switch E-22 in good condition?
YES : Go to Step 6.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the rear air conditioning works normally.

AC204176

CONNECTOR : E-20

AY

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

AC204175

CONNECTOR : E-22

AG

HARNESS SIDE

FLOOR 
COSOLE

1
7

2
8

10

11

5

13

6

14

12

4

9

3

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-57

STEP 6. Check the wiring harness between rear A/C 
control unit connector E-20 (terminal 3, 4 and 8) and rear 
A/C switch connector E-22 (terminal 5, 3 and 13).

NOTE: Also check intermediate connector D-112. If intermedi-
ate connector D-112 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 rear A/C control unit 

connector E-20 (terminal 3, 4 and 8) and rear A/C switch 
connector E-22 (terminal 5, 3 and 13) in good condition?
YES : Go to Step 7.
NO :  Repair the wiring harness. Check that the rear air 

conditioning works normally.

AC204176

CONNECTOR : E-20

AY

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

AC204175

CONNECTOR : E-22

AG

HARNESS SIDE

FLOOR 
COSOLE

1
7

2
8

10

11

5

13

6

14

12

4

9

3

AC204171 AL

CONNECTOR : D-112

2 3

27

32

28

33

16

15

4 5

19

18

29

17

34

7 8

35

22

21

9 10

30

36

31

37

25

24

23

6

20

1

14

26

11

13

12

38

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-58

STEP 7. Check the air mixing damper control motor and 
potentiometer

CAUTION

Do not apply battery voltage when the damper is in the 
MAX HOT/MAX COOL position.
Check the air mixing damper control motor by the following pro-
cedures.

When checking the air mixing damper control motor, measure 
the resistance value between the terminals 3 and 5, between 
the terminals 3 and 7. At this time, make sure that the mea-
sured resistance value changes slowly within the standard 
value.

Standard value: 1.2 

− 4.8 kΩ

Q: Does air mixing damper control motor work normally?

YES : Go to Step 8.
NO :  Replace the air mixing damper control motor. Check 

that the rear air conditioning works normally. 

LEVER 
POSITION

BATTERY 
CONNECTION

LEVER 
OPERATION

At the MAX 
COOL position

• Connect terminal 1 

to the positive 
battery terminal

• Connect terminal 2 

to the negative 
battery terminal

The lever moves 
from the MAX 
COOL position to 
the MAX HOT 
position

At the MAX 
HOT position

• Connect terminal 2 

to the positive 
battery terminal

• Connect terminal 1 

to the negative 
battery terminal

The lever moves 
from the MAX HOT 
position to the MAX 
COOL position

AC001049AB

MAX HOT POSITION

MAX 
COOL 
POSITION