Mitsubishi L200. Manual - part 849

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-12

STEP 9. Check the wiring harness between C-06 
blower switch connector terminal No.2 and C-05 
A/C switch module connector terminal No.4.

AC509611AX

Harness side

C-05

C-06

C-05

C-06

Harness side

Connectors: C-05, C-06 <LHD>

AC509932BD

Harness side

C-05

C-06

C-05

C-06

Harness side

Connectors: C-05, C-06 <RHD>

NOTE: Prior to the wiring harness inspection, check 
joint connector C-10 and repair if necessary.

• Check the engine-ECU signal line for open and 

short circuit.

• Check the blower switch signal line and earth line 

for open and short circuit.

Q: Is the check result normal?

YES : 

Go to Step 10 <Vehicles for EURO5>.

YES : 

Go to Step 12 <Except for EURO5>.

NO : 

Repair the wiring harness.

STEP 10. Connector check: C-103 engine-ECU 
connector

AC903853

BX

Connector: C-103 <LHD>

C-103 (B)

Harness side

AC903865 BB

Connector: C-103 <RHD>

Harness side

C-103 (B)

Q: Is the check result normal?

YES : 

Go to Step 11.

NO : 

Repair the connector.

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-13

STEP 11. Check the wiring harness between C-
103 engine-ECU connector terminal No.125 and 
C-05 A/C switch module connector terminal No.4.

AC509611AV

Connector: C-05 <LHD>

Harness side

AC903853

BX

Connector: C-103 <LHD>

C-103 (B)

Harness side

AC509932 BA

Harness side

Connector: C-05 <RHD>

AC903865 BB

Connector: C-103 <RHD>

Harness side

C-103 (B)

NOTE: Prior to the wiring harness inspection, check 
intermediate connector C-52 <LHD> or C-34 
<RHD>, and repair if necessary.

• Check the engine-ECU signal line for open and 

short circuit.

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Repair the wiring harness.

STEP 12. Connector check: C-21 A/C evaporator 
air outlet thermistor connector

AC509611BA

Connector: C-21 <LHD>

Harness side

AC509932BF

Harness side

Connector: C-21 <RHD>

Q: Is the check result normal?

YES : 

Go to Step 13.

NO : 

Repair the connector.

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-14

STEP 13. Resistance measurement at the C-21 A/
C evaporator air outlet thermistor connector.

AC509611BA

Connector: C-21 <LHD>

Harness side

AC509932BF

Harness side

Connector: C-21 <RHD>

(1) Disconnect the connector, and measure at the 

wiring harness side.

AC403234

Connector C-21 
(Harness side)

CE

(2) Measure the resistance between terminal 1 and 

body earth.

OK: Continuity (Less than 2

Ω)

Q: Is the check result normal?

YES : 

 Go to Step 15.

NO : 

Go to Step 14.

STEP 14. Check the wiring harness between C-05 
A/C switch module connector terminal No.5 and 
body earth.

AC509611AV

Connector: C-05 <LHD>

Harness side

AC509932 BA

Harness side

Connector: C-05 <RHD>

• Check the A/C switch module earth 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

HEATER, AIR CONDITIONER AND VENTILATION

55A-15

STEP 15. Check the wiring harness between C-05 
A/C switch module connector terminal No.3 and 
C-21 A/C evaporator air outlet thermistor 
connector terminal No.2.

AC509611BB

Harness side

C-05

C-21

C-05

C-21

Harness side

Connector: C-05, C-21 <LHD>

AC509932BI

Harness side

C-05

C-21

C-05

C-21

Harness side

Connector: C-05, C-21 <RHD>

• Check the input line for open and short circuit.

Q: Is the check result normal?

YES : 

Go to Step 16.

NO : 

Repair the wiring harness.

STEP 16. Connector check: A-38 dual pressure 
switch connector

AC509977AG

Harness side

A-38 (BR)

Connector: A-38

Q: Is the check result normal?

YES : 

Go to Step 17.

NO : 

Repair the connector.

STEP 17. Check the dual pressure switch.
Refer to 

P.55A-65

.

Q: Is the check result normal?

YES : 

Go to Step 18.

NO : 

Replace the A/C receiver assembly.

STEP 18. Check the wiring harness between C-21 
A/C evaporator air outlet thermistor connector 
terminal No.4 and A-38 dual pressure switch 
connector terminal No.2.

AC509977AG

Harness side

A-38 (BR)

Connector: A-38

AC509611BD

Harness side

C-54

C-21

C-54

C-21

Connectors: C-21, C-54 <LHD>

AC509932 BJ

Connectors: C-14, C-21 <RHD>

Harness side

C-14

C-21

C-14

C-21

NOTE: Prior to the wiring harness inspection, check 
intermediate connector C-54 <LHD> or C-14 
<RHD>, and repair if necessary.

• Check the dual pressure switch signal line.

Q: Is the check result normal?

YES : 

Go to Step 19.

NO : 

Repair the wiring harness.