Mitsubishi Lancer Evolution IX. Manual — part 542

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-41

NOTE:

Prior to the wiring harness inspection, check interme-
diate connector C-124 <LH drive vehicles> or C-122
<RH drive vehicles>, and repair if necessary.

• Check the communication line for open or short

circuit.

Q: Is the check result normal?

YES :

Go to Step 17.

NO :

Repair the wiring harness.

STEP 17. Check the magnetic clutch operation.
Refer to

P.55-123

.

Q: Can the sound of the magnetic clutch (click) be

heard?
YES :

Go to Step 18.

NO :

Replace the compressor magnet clutch.

STEP 18. Check the refrigerant temperature
switch.
Refer to

P.55-125

.

Q: Is the refrigerant temperature switch operating

properly?
YES :

Go to Step 19.

NO :

Replace the refrigerant temperature switch.

STEP 19. Check the air thermo sensor.
Refer to

P.55-120

.

Q: Is the air thermo sensor in good condition?

YES :

Go to Step 20.

NO :

Replace the air thermo sensor.

STEP 20. Check the refrigerant level.
Refer to

P.55-104

.

Q: Is the refrigerant level correct?

YES :

Go to Step 21.

NO :

Correct the refrigerant level (Refer to

P.55-104

).

STEP 21. Replace the A/C-ECU.
Check that the air conditioner works normally.

Q: Is the check result normal?

YES :

The procedure is complete.

NO :

Replace the engine-ECU.

Inspection Procedure 3: A/C Outlet Air Temperature cannot be set.

COMMENTS ON TROUBLE SYMPTOM

When the blower air temperature can not be
changed even if the preset temperature is changed,
the sensors, the air mixing damper control motor and
potentiometer or the A/C-ECU may be defective.

PROBABLE CAUSE

• Malfunction of the A/C-ECU

DIAGNOSIS PROCEDURE

M.U.T.-II/III diagnosis code

Q: Is the diagnosis code set?

YES :

Refer to diagnosis code chart

P.55-5

.

NO :

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

AC504618AH

Connector: C-122 <RHD>

C-122 (L)

AC504622AD

Connector: C-124 <LHD>

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-42

Inspection Procedure 4: The Blower does not work.

COMMENTS ON TROUBLE SYMPTOM

If the blower motor does not operate, the blower
motor circuit system may be defective.

PROBABLE CAUSES

• Malfunction of the blower motor (blower linear

controller).

• Malfunction of the automatic A/C control panel

(A/C-ECU)

• Damaged the wiring harness or connectors

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-II/III actuator test
Carry out the actuator test. (Refer to

P.55-101

)

• Item 01, 02, 03, 04: Blower motor

Q: Does the blower motor work normally?

YES :

Replace the automatic A/C control panel

(A/C-ECU).

NO :

Go to Step 2.

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

Blower Circuit

FUSIBLE
LINK

1

IGNITION
SWITCH (IG2)

BLOWER
RELAY

A/C-ECU

<RHD>

<LHD>

BLOWER MOTOR
(BLOWER
LINEAR
CONTROLLER)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-43

STEP 2. Voltage measurement at the C-34 blower
linear controller connector.

(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Turn the ignition switch to the ON position.

(3) Measure the voltage between terminal 6 and

body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 15.

NO :

Go to Step 3.

STEP 3. Check the blower relay.
Refer to GROUP 55A, On-vehicle Service

− Power

relay check

P.55-107

.

Q: Is the blower relay in good condition?

YES :

Go to Step 4.

NO :

Replace the blower relay.

STEP 4. Voltage measurement at C-216 blower
relay connector.

(1) Remove the relay, and measure at the junction

block side.

(2) Turn the ignition switch to the ON position.

(3) Voltage between terminal 1 and body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Go to Step 5.

AC504617AC

Connector: C-34 <LHD>

Harness side

AC504618AC

Connector: C-34 <RHD>

Harness side

AC301541JY

Connector C-34
(Harness side)

AC504692AB

Connector: C-216 <LHD>

Junction block side

Junction block (Front view)

AC504694AB

Junction block (Front view)

Connector: C-216 <RHD>

Junction block side

AC301541JZ

Connector C-216
(Junction block side)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-44

STEP 5. Connector check: C-216 blower relay
connector

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the connector.

STEP 6. Check the wiring harness between C-216
blower relay connector terminal No.1 and the
ignition switch (IG2).

NOTE: Prior to the wiring harness inspection, check
junction block connector C-211, and repair if neces-
sary.

• Check the blower relay 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

P.00-5

).

NO :

Repair the wiring harness.

AC504692AB

Connector: C-216 <LHD>

Junction block side

Junction block (Front view)

AC504694AB

Junction block (Front view)

Connector: C-216 <RHD>

Junction block side

AC504633AC

Connector: C-211, C-216 <LHD>

Junction block side

Junction block (Front view)

Harness side

C-211

C-211

C-216

C-216

AC504635AC

Harness side

Junction block (Front view)

C-211

C-216

Junction block side

C-216

C-211

Connector: C-211, C-216 <RHD>