Mitsubishi L200. Manual - part 869

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-5

DIAGNOSIS CODE PROCEDURES

Code No.B1001,B1002: Interior temperature sensor system

Interior Temperature Sensor Circuit

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 : Grey     R : Red     P : Pink     V : Violet     PU : Purple

AC805734 AC

DIAGNOSIS CODE SET CONDITION
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 A/C control panel (A/

C-ECU)

B1061

Potentiometer system for mode selection damper (short 
to power supply)

P.55B-18

Moved to DEF 
position

B1062

Potentiometer system for mode selection damper (short 
to earth or open circuit)

P.55B-18

B1065

Motor drive system for mode selection damper 

P.55B-20

−

Code No.

Diagnostic item

Reference page Service data 

display 
contents when 
diagnosis code 
is set

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-6

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-44 A/C-ECU 
connector and C-48 interior temperature sensor 
connector

AC509611BM

Harness side

Connector: C-44 <LHD>

AC509613 BZ

Connectors: C-48 <LHD>

C-48

Harness side

C-48

AC509932 BP

Harness side

Connectors: C-44, C-48 <RHD>

C-44

C-48

C-44

Harness side

C-48

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the connector.

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-7

STEP 2. Check the wiring harness between C-44 
A/C-ECU connector (terminals 40 and 38) and C-
48 interior temperature sensor connector 
(terminals 2 and 1).

AC509611BM

Harness side

Connector: C-44 <LHD>

AC509613 BZ

Connectors: C-48 <LHD>

C-48

Harness side

C-48

AC509932 BP

Harness side

Connectors: C-44, C-48 <RHD>

C-44

C-48

C-44

Harness side

C-48

NOTE: 

AC509611DV

Connector: C-138 <LHD>

C-138 (L)

AC509932DX

Connector: C-138 <RHD>

C-138 (L)

Prior to the wiring harness inspection, check joint 
connector C-138, and repair if necessary.

• Check the sensor signal line and earth line for 

open and short circuit.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the wiring harness.

STEP 3. Check the interior temperature sensor.
Refer to 

P.55B-99

.

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Replace the interior temperature sensor.

STEP 4. Check whether the diagnosis code is 
reset.

Q: Is the check result normal?

YES : 

The trouble can be an intermittent 

malfunction (Refer to GROUP 00, How to 
Cope with Intermittent Malfunction ).

NO : 

Replace the automatic A/C control panel (A/
C-ECU).

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-8

Code No. B1011,B1012: Ambient temperature sensor system

Ambient Temperature Sensor Circuit

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 : Grey     R : Red     P : Pink     V : Violet     PU : Purple

COMMENTS ON TROUBLE SYMPTOM
This code is set when the ambient temperature sen-
sor circuit is open (Code No.B1012) or is short (Code 
No.B1011).

PROBABLE CAUSES

• Malfunction of the ambient temperature sensor

• Damaged the wiring harness and connectors

• Malfunction of the automatic A/C control panel (A/

C-ECU)