Mitsubishi Grandis. Manual - part 282

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-13

Step 2. Connector check: A-28 ambient 
temperature sensor connector and C-106 
A/C-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector.

AC310403

Connector: A-28 <LHD>

A-28 (B)

AB

Harness side

AC310398

Connector: A-28 <RHD>

A-28 (B)

AB

Harness side

AC310613

AB

Connector: C-106 <LHD>

Harness side

AC310631AB

Connectors: C-106 <RHD>

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-14

Step 3. Check the wiring harness between A-28 
ambient temperature sensor connector 
(terminals 1 and 2) and C-106 A/C-ECU connector 
(terminals 1 and 24).

AC310403

Connector: A-28 <LHD>

A-28 (B)

AB

Harness side

AC310398

Connector: A-28 <RHD>

A-28 (B)

AB

Harness side

AC310614

BD

Connectors: C-106, C-125 <LHD>

C-106

C-125

C-106

Harness side

C-125

AC310613

AB

Connector: C-106 <LHD>

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-15

NOTE: Prior to the wiring harness inspection, check 
intermediate connector C-125, and repair if 
necessary.

• 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.

Step 4. Check the ambient temperature sensor.

Refer to 

P.55-211

.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Replace the ambient 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. B1021,B1022: Air thermo sensor system 

COMMENTS ON TROUBLE SYMPTOM

This code is set when the air thermo sensor circuit is 
open (Code No.B1022) or is short (Code No.B1021).

POSSIBLE CAUSES

• Malfunction of the air thermo 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 03: Air thermo sensor

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Go to Step 2.

AC310628AB

Connector: C-125 <RHD>

AIR THERMO
SENSOR

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

Air Thermo Sensor Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-16

Step 2. Connector check: C-106 A/C-ECU 
connector and C-05 air thermo 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 19) and C-05 
air thermo sensor connector (terminals 2 and 1).

• 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

AE

Connectors: C-05, C-106 <LHD>

Harness side

C-106

C-05

C-106

Harness side

C-05

AC310632 AC

Connectors: C-05, C-106 <RHD>

Harness side

C-05

C-106

C-05

C-106

Harness side

AC310614

AE

Connectors: C-05, C-106 <LHD>

Harness side

C-106

C-05

C-106

Harness side

C-05

AC310632 AC

Connectors: C-05, C-106 <RHD>

Harness side

C-05

C-106

C-05

C-106

Harness side