Mitsubishi Lancer Evolution IX. Manual - part 533

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-5

TROUBLESHOOTING

DIAGNOSIS TROUBLESHOOTING FLOW

M1554004700102

Refer to GROUP 00, How to Use Troubleshoot-
ing/Inspection Service Points 

P.00-5

.

DIAGNOSIS FUNCTION

M1554004800176

How to read diagnosis code

Connect the M.U.T.-II/III to the 16-pin diagnosis con-
nector to read diagnosis code (Refer to GROUP 00, 
How to Use Troubleshooting/Inspection Service 
Points 

P.00-5

).

How to erase diagnosis code

Refer to GROUP 00, How to Use Troubleshoot-
ing/Inspection Service Points 

P.00-5

.

DIAGNOSIS CODE CHART

M1554004900537

MB992006

Extra fine probe

Continuity check and voltage 
measurement at harness wire 
or connector

Tool

Number

Name

Use

MB992006

Code No.

Diagnostic item

Reference page

11

Interior temperature senor system (open circuit)

P.55-6

12

Interior temperature sensor system (short circuit)

13

Outside thermo sensor system (open circuit)

P.55-8

14

Outside thermo sensor system (short circuit)

15

Heater water temperature sensor system (open circuit)

P.55-11

16

Heater water temperature sensor system (short circuit)

21

Air thermo sensor system (open circuit)

P.55-14

22

Air thermo sensor system (short circuit)

31

Air mixing damper control motor and potentiometer sensor system

P.55-17

32

Mode selection damper control motor and potentiometer sensor 
system

P.55-20

41

Air mixing damper control motor and potentiometer activating 
system

P.55-23

42

Mode selection damper control motor and potentiometer activating 
system

P.55-26

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-6

DIAGNOSTIC TROUBLE CODE 
PROCEDURES

Code No.11, 12: Interior Temperature Sensor System

COMMENTS ON TROUBLE SYMPTOM

This code is set when the interior temperature sensor 
circuit is open (Code No.11) or is short (Code No.12).

PROBABLE CAUSES

• Malfunction of the interior temperature sensor

• Damaged the wiring harness or connectors

• Malfunction of the automatic A/C control panel 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Check the interior temperature sensor.
Refer to 

P.55-117

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Replace the interior temperature sensor.

Interior Temperature 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

INTERIOR
TEMPERATURE
SENSOR

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-7

STEP 2. Connector check: C-36 A/C-ECU 
connector and C-142 interior temperature 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-36 
A/C-ECU connector (terminals 1 and 20) and 
C-142 interior temperature 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 : 

Replace the automatic A/C control panel 

(A/C-ECU)

NO : 

Repair the wiring harness.

AC504641AC

Connector: C-36, C-142 <LHD>

Harness side

C-142 (B)

C-36 (B)

C-36

C-142

AC504618AJ

Connector: C-36 <RHD>

Harness side

C-36 (B)

AC504625AD

Connector: C-142 <RHD>

Harness side

C-142 (B)

AC504641AC

Connector: C-36, C-142 <LHD>

Harness side

C-142 (B)

C-36 (B)

C-36

C-142

AC504618AJ

Connector: C-36 <RHD>

Harness side

C-36 (B)

AC504625AD

Connector: C-142 <RHD>

Harness side

C-142 (B)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-8

Code No.13, 14: Outside Thermo Sensor System

COMMENTS ON TROUBLE SYMPTOM

This code is set when the outside thermo sensor cir-
cuit is open (Code No.13) or is short (Code No.14).

PROBABLE CAUSES

• Malfunction of the outside thermo sensor

• Damaged the wiring harness and connectors

• Malfunction of the automatic A/C control panel 

(A/C-ECU)

DIAGNOSIS PROCEDURE

STEP 1. Check the outside thermo sensor.
Refer to 

P.55-121

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Replace the outside thermo sensor.

Outside Thermo 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

OUTSIDE
THERMO
SENSOR