Mitsubishi Grandis. Manual - part 281

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-9

B1055

Motor drive system for rear air mix damper <vehicles 
with dual automatic A/C>

P.55-29

−

B1061

Potentiometer system for air outlet switching damper 
(short to power supply) <LHD>

P.55-32

Moved to DEF 
position

Potentiometer system for air outlet switching damper 
(short to power supply) <RHD>

P.55-34

B1062

Potentiometer system for air outlet switching damper 
(short to earth or open circuit) <LHD>

P.55-32

Potentiometer system for air outlet switching damper 
(short to earth or open circuit) <RHD>

P.55-34

B1065

Motor drive system for air outlet switching damper 

P.55-35

−

U1073

Bus off error

P.55-38

−

U1100

Engine-related CAN time-out

P.55-38

−

U1109

ETACS related CAN communication time-out

P.55-40

−

U1113

Multi-centre display-related CAN time-out

P.55-41

−

U1120

Engine-related failure data

P.55-42

−

Code No.

Diagnostic item

Reference page Service data 

display 
contents when 
diagnosis code 
is set

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-10

DIAGNOSTIC TROUBLE CODE 
PROCEDURES

Code No. B1001,B1002: Interior temperature sensor system 

COMMENTS ON TROUBLE SYMPTOM

This code is set when the interior temperature sensor 
circuit is open (Code No.B1002) or is short (Code 
No.B1001).

POSSIBLE CAUSES

• Malfunction of the interior temperature sensor

• 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 01: Inside temperature sensor

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 2.

A/C-ECU

INTERIOR
TEMPERATURE
SENSOR

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

Interior Temperature Sensor Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-11

Step 2. Connector check: C-106 A/C-ECU 
connector and C-26 interior temperature sensor 
connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector.

Step 3. Check the wiring harness between C-106 
A/C-ECU connector (terminals 1 and 18) and C-26 
interior temperature sensor connector (terminals 
1 and 2).

• Check the sensor signal line and earth line for 

open or short circuit.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the wiring harness.

AC310614

AB

Connectors: C-26, C-106 <LHD>

Harness side

2 1

C-26

C-106

C-26

C-106

Harness side

AC310632 AB

Connectors: C-26, C-106 <RHD>

Harness side

2 1

C-26

C-106

C-26

C-106

Harness side

AC310614

AB

Connectors: C-26, C-106 <LHD>

Harness side

2 1

C-26

C-106

C-26

C-106

Harness side

AC310632 AB

Connectors: C-26, C-106 <RHD>

Harness side

2 1

C-26

C-106

C-26

C-106

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-12

Step 4. Check the interior temperature sensor.

Refer to 

P.55-211

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the interior temperature sensor.

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. B1011,B1012: Ambient temperature sensor system 

COMMENTS ON TROUBLE SYMPTOM

This code is set when the ambient temperature 
sensor circuit is open (Code No.B1012) or is short 
(Code No.B1011).

POSSIBLE CAUSES

• Malfunction of the ambient temperature sensor

• Damaged the wiring harness and 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 02: Ambient temperature sensor

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 2.

A/C-ECU

AMBIENT
TEMPERATURE
SENSOR

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

Ambient Temperature Sensor Circuit