Mitsubishi Outlander (2013+). Manual - part 738

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-8

DIAGNOSIS CODE PROCEDURES

Code No.B10C0: Interior temperature sensor system (short circuit)

 

Code No.B10C1: Interior temperature sensor system (open circuit)

COMMENTS ON TROUBLE SYMPTOM

This code is set when the interior temperature sensor 
circuit is short (Code No.B10C0) or is open (Code 
No.B10C1)

PROBABLE CAUSES

• Malfunction of the interior temperature sensor

• Damaged the wiring harness or connectors

• Malfunction of the heater controller assembly 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Check that the following service data display con-
tents are normal. (Refer to 

P.55-29

).

Item No.63: Interior temperature sensor 

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Go to Step 2.

STEP 2. Check of open and short circuit in SENG 
and INC line between interior temperature sensor 
and heater controller assembly (A/C-ECU) 
connector.

NOTE: Prior to the wiring harness inspection, check 
joint connector and repair if necessary.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector(s) or wiring harness.

STEP 3. Check the interior temperature sensor.
Refer to 

P.55-50

.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Replace the air mixing damper control 
motor and potentiometer.

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code set?

YES : 

Replace the heater controller assembly 

(A/C-ECU).

NO : 

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

Code No.B1031: Fin thermo Sensor system (short circuit)

 

Code No.B1032: Fin thermo Sensor system (open circuit)

COMMENTS ON TROUBLE SYMPTOM

This code is set when the fin thermo sensor circuit is 
short (Code No.B1031) or is open (Code No.B1032).

PROBABLE CAUSES

• Malfunction of the fin thermo sensor

• Damaged wiring harness or connectors

• Malfunction of the heater controller assembly 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Check that the following service data display con-
tents are normal. (Refer to 

P.55-29

).

Item No.20: Air thermo sensor 

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Go to Step 2.

STEP 2. Check of open and short circuit in + and 
- line between fin thermo sensor and auto heater 
controller assembly (A/C-ECU) connector.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector(s) or wiring harness.

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-9

STEP 3. Check the fin thermo sensor.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Replace the air mixing damper control 
motor and potentiometer.

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is the diagnosis code set?

YES : 

Replace the heater controller assembly 

(A/C-ECU).

NO : 

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

Code No. B1079: A/C Refrigerant leaks

COMMENTS ON TROUBLE SYMPTOM

If this code is set, the refrigerant level may not be 
appropriate, or the A/C pressure sensor may be 
faulty (If this code is set, the A/C indicator will flash).

PROBABLE CAUSES

• Inadequate refrigerant level 

• Malfunction of the A/C pressure sensor

• Malfunction of the ambient temperature sensor

• Damaged wiring harness or connectors

• Malfunction of the heater controller assembly 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Check the condenser assembly
Check that the condenser assembly is not wet.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Wait until the condenser is dry, and check 
that no diagnosis code is set.

STEP 2. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the CAN bus lines. (Refer to GROUP 
54C, Troubleshooting ). 

STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis code related to the A/C is 
not set.

Q: Is the diagnosis code set?

YES : 

Carry out the diagnosis code procedures. 

Refer to 

P.55-7

. 

NO : 

Go to Step 4.

STEP 4. M.U.T.-III data list
Check that the following service data display con-
tents are normal. (Refer to 

P.55-29

)

Item No.19: Ambient temperature sensor 

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Refer to Inspection Procedure 5: Ambient 
temperature sensor system 

P.55-27

.

STEP 5. Check the A/C pressure sensor
Refer to 

P.55-40

.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Replace the A/C pressure sensor.

STEP 6. Refrigerant level check
Refer to 

P.55-34

.

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Correct the refrigerant level.

STEP 7. Check whether the diagnosis code is 
reset

Q: Is the diagnosis code set?

YES : 

Refer to Inspection Procedure 11: A/C 

pressure sensor system 

P.55-27

.

NO : 

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

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-10

Code No. U0141: ETACS-ECU CAN time-out

CAUTION

If diagnosis code No.U0141 is set in the heater 
controller assembly (A/C-ECU), diagnose the 
CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

TROUBLE JUDGMENT

The heater controller assembly (A/C-ECU) receives 
air conditioner operation-related signal from the 
ETACS-ECU via the CAN bus lines. If the heater 
controller assembly (A/C-ECU) can not receive the 
air conditioner operation-related signal at all on the 
ETACS-ECU, diagnosis code No.U0141 will be set.

COMMENTS ON TROUBLE SYMPTOM

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the ETACS-ECU and the heater 
controller assembly (A/C-ECU), the power supply 
system to the ETACS-ECU, the ETACS-ECU 
itself, or the A/C-ECU may be faulty.

Past trouble

• Carry out diagnosis with particular emphasis on 

connector(s) or wiring harness in the CAN bus 
lines between the ETACS-ECU and the heater 
controller assembly (A/C-ECU), and the power 
supply system to the ETACS-ECU. For diagnosis 
procedures, refer to "How to treat past trouble" 
(Refer to GROUP 00 

− How to Treat Past Trouble 

).

NOTE: For a past trouble, you can not find it by the 

M.U.T.-III CAN bus diagnostics even if there is 
any failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Cope with Intermittent Mal-
function  and check the CAN bus lines. You can 
narrow down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54C 

−

 CAN Bus Line Diagnos-

tic Flow ).

CAUTION

If the ignition switch is turned on without starting 
the engine and then three minutes pass, the 
heater controller assembly (A/C-ECU) may store 
U0141 as past trouble.

PROBABLE CAUSES

• Damaged wiring harness or connectors

• Malfunction of the ETACS-ECU 

• Malfunction of the heater controller assembly 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C, Troubleshooting ). On completion, go 
to Step 6.

STEP 2. M.U.T.-III other system diagnosis code
Check whether the ETACS-related diagnosis code is 
set.

Q: Is the diagnosis code set?

YES : 

Diagnose the ETACS-ECU. Refer to .

NO : 

Go to Step 3

STEP 3. M.U.T.-III other system diagnosis code
Check if a diagnosis code, which relates to CAN 
communication-linked systems below, is set.

• Combination meter 

U0141: ETACS-ECU timeout

Q: Is the diagnosis code set?

YES : 

Go to Step 4

NO : 

Go to Step 5

STEP 4. Check whether the diagnosis code is 
reset.
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) to ON
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code set?

YES : 

Replace the ETACS-ECU, and then go to 

Step 6.

NO : 

A poor connection, open circuit or other 
intermittent malfunction in the CAN bus line 
between the ETACS-ECU and the heater 
controller assembly (A/C-ECU) (Refer to 
GROUP 00 

− How to Cope with Intermittent 

Malfunction ).

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-11

STEP 5. Check whether the diagnosis code is 
reset.
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) to ON
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code set?

YES : 

Replace the heater controller assembly 

(A/C-ECU), and then go to Step 6. 

NO : 

A poor connection, open circuit or other 
intermittent malfunction in the CAN bus line 
between the ETACS-ECU and the heater 
controller assembly (A/C-ECU) (Refer to 
GROUP 00 

− How to Cope with Intermittent 

Malfunction ).

STEP 6. Check whether the diagnosis code is 
reset.
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) to ON
(3) Check if the diagnosis code is set.

Q: Is the diagnosis code set?

YES : 

Return to Step 1.

NO : 

The procedure is complete.

Code No. U0155: Meter CAN time-out

CAUTION

If diagnosis code No.U0155 is set in the heater 
controller assembly (A/C-ECU), diagnose the 
CAN main bus line.

CAUTION

Whenever the ECU is replaced, ensure that the 
communication circuit is normal.

TROUBLE JUDGMENT

The heater controller assembly (A/C-ECU) receives 
air conditioner control-related signals from the com-
bination meter via the CAN bus lines. If the ECU can-
not receive any of the air conditioner control-related 
signals from the combination meter, diagnosis code 
U0155 will be stored.

COMMENTS ON TROUBLE SYMPTOM

Current trouble

• Connector(s) or wiring harness in the CAN bus 

lines between the combination meter and the 
A/C-ECU, the power supply system to the combi-
nation meter, the combination meter itself, or the 
heater controller assembly (A/C-ECU) may be 
faulty.

Past trouble

• Carry out diagnosis with particular emphasis on 

connector(s) or wiring harness in the CAN bus 
lines between the heater controller assembly 
(A/C-ECU) and the combination meter, and the 
power supply system to the combination meter. 
For diagnosis procedures, refer to "How to treat 
past trouble" (Refer to GROUP 00 

− How to Treat 

Past Trouble ).

NOTE: For a past trouble, you can not find it by the 

M.U.T.-III CAN bus diagnostics even if there is 
any failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Cope with Intermittent Mal-
function  and check the CAN bus lines. You can 
narrow down the possible cause of the trouble by 
referring to the diagnosis code, which is set 
regarding the CAN communication-linked ECUs 
(Refer to GROUP 54C 

−

 CAN Bus Line Diagnos-

tic Flow ).

CAUTION

If the ignition switch is turned to the ON position 
without starting the engine, the diagnosis code 
U0168 (past trouble) may be set to the heater 
controller assembly (A/C-ECU) after three min-
utes.

PROBABLE CAUSES

• Damaged wiring harness or connectors

• Malfunction of the combination meter 

• Malfunction of the heater controller assembly 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C, Troubleshooting ). On completion, go 
to Step 6.