Mitsubishi Grandis. Manual - part 285

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-25

Step 3. Check the wiring harness between C-106 
A/C-ECU connector (terminals 14, 22 and 1) and 
G-13-1 rear air mixing damper control motor and 
potentiometer connector (terminals 4, 3 and 5).

NOTE: 

Prior to the wiring harness inspection, check 
intermediate connector G-13, C-15 and joint 
connector C-01, and repair if necessary.

• Check the potentiometer power supply, earth and 

signal line for open or short circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

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

Refer to 

P.55-216

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the rear 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

.)

AC310614

AG

Connectors: C-01, C-106 <LHD>

C-01

C-106

C-01

C-106

Harness side

AC311185

Connectors: G-13, G-13-1

AB

G-13-1

G-13

G-13-1

G-13

Harness side

AC310615

AD

Connector: C-15 <LHD>

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-26

Code No. B1051,B1052: Potentiometer system for rear air mix damper <vehicles with RHD 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?

YES : 

Go to Step 5.

NO : 

Go to Step 2.

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

55-27

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.

AC310631AB

Connectors: C-106 <RHD>

Harness side

AC311184

Connector: G-13-1

AB

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-28

Step 3. Check the wiring harness between C-106 
A/C-ECU connector (terminals 14, 22 and 1) and 
G-13-1 rear air mixing damper control motor and 
potentiometer connector (terminals 4, 3 and 5).

NOTE: 

Prior to the wiring harness inspection, check 
intermediate connector G-13 and C-15, and repair if 
necessary.

• Check the potentiometer power supply, earth and 

signal line for open or short circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

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

Refer to 

P.55-216

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the rear 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

.)

AC310631AB

Connectors: C-106 <RHD>

Harness side

AC311185

Connectors: G-13, G-13-1

AB

G-13-1

G-13

G-13-1

G-13

Harness side

AC310628AE

Connector: C-15 <RHD>