Mitsubishi L200. Manual - part 889

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-85

STEP 5. Check the wiring harness between C-43 
A/C-ECU connector terminal No.8 and the fusible 
link (20).

AC509611AR

Connector: C-43 <LHD>

Harness side

AC509932AS

Harness side

Connector: C-43 <RHD>

NOTE: 

AC509613

Connector: C-132 <LHD>

AD

C-132 (GR)

AC509930AE

Connector: C-132 <RHD>

C-132 (GR)

AC509934

Connectors: C-209, C-213 <LHD>

Junction block (Front view)

C-213

C-209

C-213

C-209

AC

Harness side

Harness side

AC509936

Connectors: C-209, C-213 <RHD>

C-213

C-209

AC

Junction block 
(Front view)

C-213

C-209

Harness side Harness side

Prior to the wiring harness inspection, check joint 
connector C-132, junction block connector C-213 
and C-209, and repair if necessary.

• Check the A/C-ECU power supply line for open 

circuit.

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 : 

Repair the wiring harness.

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-86

STEP 6. Resistance measurement at the C-43 A/
C-ECU connector.

AC509611AR

Connector: C-43 <LHD>

Harness side

AC509932AS

Harness side

Connector: C-43 <RHD>

(1) Disconnect the connector, and measure at the 

wiring harness side.

AC310506

Connector C-43 
(Harness side)

ID

(2) Continuity between terminal 22 and body earth

OK: Continuity (Less than 2

Ω)

Q: Is the check result normal?

YES : 

Replace the A/C-ECU.

NO : 

Go to Step 7.

STEP 7. Check the wiring harness between C-43 
A/C-ECU connector terminal No.22 and body 
earth.

AC509611AR

Connector: C-43 <LHD>

Harness side

AC509932AS

Harness side

Connector: C-43 <RHD>

NOTE: 

AC509611AU

Connector: C-120 <LHD>

C-120 (L)

AC509932AZ

Connector: C-120 <RHD>

C-120 (L)

Prior to the wiring harness inspection, check joint 
connector C-120, and repair if necessary.

• Check the A/C-ECU earth line for open circuit.

Q: Is the check result normal?

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-87

YES : 

The trouble can be an intermittent 

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

NO : 

Repair the wiring harness.

Inspection Procedure 9: The outlet air temperature can not be changed even if the amount of solar 
radiation changes

Photo Sensor Circuit

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

A/C-ECU

PHOTO SENSOR

AC806061

CIRCUIT OPERATION
When the blower air temperature can not be 
changed even if the amount of solar radiation is 
changed, the photo sensor may be defective. 

PROBABLE CAUSES

• Malfunction of photo sensor

• Damaged harness wires and connectors

• Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.
Check whether the A/C sets a diagnosis code or not.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Refer to diagnosis code chart 

P.55B-4

.

STEP 2. M.U.T.-III data list.
Check that the following data list display contents are 
normal. (Refer to 

P.55B-89

.)

• Item 67: Photo sensor

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Go to Step 4.

STEP 3. Recheck the trouble symptom

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-88

STEP 4. Connector check: C-41 photo sensor 
connector and C-44 A/C-ECU connector 

AC510204 AB

Connectors: C-41, C-44 <LHD>

Harness side

C-44

C-41

C-41

C-44

Harness side

AC510216AB

Connectors: C-41, C-44 <RHD>

Harness side

C-44

C-41

C-41

C-44

Harness side

Q:  Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the connector.

STEP 5. Check the wiring harness between C-41 
photo sensor connector (terminal 1 and 2) and C-
44 A/C-ECU connector (terminal 41 and 38).

AC510204 AB

Connectors: C-41, C-44 <LHD>

Harness side

C-44

C-41

C-41

C-44

Harness side

AC510216AB

Connectors: C-41, C-44 <RHD>

Harness side

C-44

C-41

C-41

C-44

Harness side

NOTE: 

AC509932BG

Connectors: C-137,  C-138 <RHD>

C-138 (L)

C-138

C-137 (L)

C-137

AC509611CY

Connectors: C-137,  C-138 <LHD>

C-138 (L)

C-138

C-137 (L)

C-137

Prior to the wiring harness inspection, check joint 
connector C-137 and C-138, and repair if necessary.

• Check the A/C-ECU input line for open circuit.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness. Check that the A/
C works normally.