Mitsubishi Montero (2004+). Manual - part 596

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-27

STEP 6. Measure the resistance at rear heater control unit 
connector E-01 <vehicles with rear heater>, rear cooler 
control unit connector E-09 <vehicles with rear cooler> or 
rear A/C control unit connector E-20 <vehicles with rear 
A/C>.

(1) Disconnect rear heater control unit connector E-01 

<vehicles with rear heater>, rear cooler control unit 
connector E-09 <vehicles with rear cooler> or rear A/C 
control unit connector E-20 <vehicles with rear A/C>, and 
measure at the wiring harness side.

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

• The measured value should be 2 ohms or less.

Q: Does the measured resistance value correspond with 

this range?
YES : Replace the rear heater control unit <vehicles with 

rear heater>, rear cooler control unit <vehicles with 
rear cooler> or rear A/C control unit <vehicles with 
rear A/C>, and check that the rear air conditioning 
works normally.

NO :   Go to Step 7.

AC204194

CONNECTORS : E-01, E-09, E-20

AN

E-01,
E-09,
E-20

E-01 <VEHICLES WITH REAR HEATER>
E-09 <VEHICLES WITH REAR COOLER>
E-20 <VEHICLES WITH REAR A/C>

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

AC205150

7

8

3

10 9

2

4

11

1312

5

14

6

1

AB

CONNECTOR E-01, E-09, E-20
(HARNESS SIDE)

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-28

STEP 7. Check the wiring harness between rear heater 
control unit connector E-01 (terminal 2) <vehicles with rear 
heater>, rear cooler control unit connector E-09 (terminal 
2) <vehicles with rear cooler> or rear A/C control unit 
connector E-20 (terminal 2) <vehicles with rear A/C> and 
the ground.

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

P.00E-2

.

Q: Is the wiring harness between rear heater control unit 

connector E-01 (terminal 2) <vehicles with rear heater>, 
rear cooler control unit connector E-09 (terminal 2) 
<vehicles with rear cooler> or rear A/C control unit 
connector E-20 (terminal 2) <vehicles with rear A/C> and 
the ground in good condition?
YES : Replace the rear heater control unit connector E-01 

<vehicles with rear heater>, rear cooler control unit 
connector E-09 <vehicles with rear cooler> or rear 
A/C control unit connector E-20 <vehicles with rear 
A/C>, and check that the rear air conditioning works 
normally.

NO :  Repair the wiring harness. Check that the rear air 

conditioning works normally.

AC204194

CONNECTORS : E-01, E-09, E-20

AN

E-01,
E-09,
E-20

E-01 <VEHICLES WITH REAR HEATER>
E-09 <VEHICLES WITH REAR COOLER>
E-20 <VEHICLES WITH REAR A/C>

HARNESS SIDE

7

8

3

10 9

2

4

11

1312

5

14

6

1

AC204170

CONNECTOR : D-30

AJ

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

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-29

INSPECTION PROCEDURE 2: Rear Air Conditioning Outlet Air Temperature does not Increase 
<Vehicles with Rear Heater>

Air Mixing Damper Control Motor and Potentiometer Circuit

REAR AIR CONDITIONING DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-30

DIAGNOSIS

STEP 1. Check the rear heater switch (temperature control 
switch).

Connect the tester between the connector terminal number 3 
and number 5, between the terminal number 5 and number 13 
and make sure that the resistance value changes slowly within 
the standard value.

Standard value: 0 

− 3 kΩ

Q: Is the check result normal?

YES :  Go to Step 2.
NO :  Replace the rear air-conditioner switch.

AC204170

CONNECTOR : D-30

BC

AC204171

CONNECTOR : D-112

AU

AC204176

CONNECTORS : E-01, E-06, E-12

BP

E-12

E-01

E-06

AC204175

CONNECTOR : E-21

AJ

AC204179

CONNECTORS : G-23, G-25

AZ

G-23

G-25

AC204698 AT

G-25-1

G-25-2

CONNECTORS : G-25-1, G-25-2

AC205161

1
7

2
8

10 11

5

13

6

14

12

4

9

3