Mitsubishi Grandis. Manual - part 284

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-21

Code No.B1045: Motor drive system for the front air mix damper

COMMENTS ON TROUBLE SYMPTOM

This code is set when the air mixing damper cannot 
be rotated to the preset opening angle.

POSSIBLE CAUSES

• Malfunction of the front air mixing damper control 

motor and potentiometer

• Malfunction of the automatic air conditioner 

control panel (A/C-ECU)

• Damaged the wiring harness or connectors

DIAGNOSIS

Step 1. MUT-III actuator test

Check that the following actuator test can be 
executed normally.

• Item 10: F.Air mix dumper motor: 0%

• Item 11: F.Air mix dumper motor: 50%

• Item 12: F.Air mix dumper motor: 100%

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 2.

A/C-ECU

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Gray     R : Red     P : Pink     V : Violet

FRONT AIR MIXING DAMPER CONTROL
MOTOR AND POTENTIOMETER

Front Air Mix Damper Control Motor And Potentiometer Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-22

Step 2. Connector check: C-105 A/C-ECU 
connector and C-11 front air mixing damper 
control motor and potentiometer connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector.

Step 3. Check the wiring harness between C-105 
A/C-ECU connector (terminals 31 and 32) and 
C-11 front air mixing damper control motor and 
potentiometer connector (terminals 1 and 2).

• Check the motor activating lines for open or short 

circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

AC310615

Connector: C-11 <LHD>

AC

Harness side

AC310628

Connector: C-11 <RHD>

AD

Harness side

AC310613

AC

Connector: C-105 <LHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

AC310631AC

Connector: C-105 <RHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

AC310615

Connector: C-11 <LHD>

AC

Harness side

AC310628

Connector: C-11 <RHD>

AD

Harness side

AC310613

AC

Connector: C-105 <LHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

AC310631AC

Connector: C-105 <RHD>

Harness side

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-23

Step 4. Check the front air mixing damper control 
motor and potentiometer.

Refer to 

P.55-208

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the air mixing damper control 
motor and potentiometer.

Step 5. MUT-III diagnosis code

Q: Is the diagnosis code set?

YES : 

Replace the automatic air conditioner 

control panel (A/C-ECU)

NO : 

The trouble can be an intermittent 
malfunction (Refer to GROUP 00, How to 
Cope with Intermittent Malfunction 

P.00-5

.)

Code No. B1051,B1052: Potentiometer system for rear air mix damper <vehicles with LHD dual 
automatic A/C>

COMMENTS ON TROUBLE SYMPTOM

This code is set when the rear air mixing damper 
control motor potentiometer does not send any 
signal to the A/C-ECU due to short or open circuit.

POSSIBLE CAUSES

• Malfunction of the rear air mixing damper control 

motor and potentiometer

• Damaged the wiring harness or connectors

• Malfunction of the automatic air conditioner 

control panel (A/C-ECU)

DIAGNOSIS

Step 1. MUT-III data list

Check that the following service data display 
contents are normal. (Refer to 

P.55-183

.)

• Item 12: R.Air mix potentiometer 

• Item 13: R.Air mix potentiometer (Target)

Q: Is the check result normal?

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Gray     R : Red     P : Pink     V : Violet

REAR AIR MIXING
DAMPER CONTROL
MOTOR AND
POTENTIOMETER

A/C-ECU

Rear Air Mixing Damper Control Motor And Potentiometer Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-24

YES : 

Go to Step 5.

NO : 

Go to Step 2.

Step 2. Connector check: C-106 A/C-ECU 
connector and G-13-1 rear air mixing damper 
control motor and potentiometer connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector.

AC310613

AB

Connector: C-106 <LHD>

Harness side

AC311184

Connector: G-13-1

AB

Harness side