Mitsubishi Lancer Evolution VI. Manual - part 122

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-40

Code No.41 Drive system of air mix damper motor
assembly

Probable cause

This diagnosis code is output if the air mix damper fails to be turned to the preset
opening.

D

Malfunction of the air mix damper motor assembly

D

Malfunction of connector, harness

D

Malfunction of the A/C-ECU

Air mix damper motor check (Refer to P.55-59.)

NG

Replace

OK

Check the following connectors:
B-39, B-05

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air mix damper motor and the
A/C-ECU.

OK

Replace the A/C-ECU.

NG

Repair

Code No.42 Drive system of air outlet changeover damper
motor assembly

Probable cause

This diagnosis code is output if the air outlet changeover damper fails to be turned
to the preset opening.

D

Malfunction of the air outlet changeover damper
motor assembly

D

Malfunction of connector, harness

D

Malfunction of the A/C-ECU

Air outlet changeover damper motor check (Refer to P.55-60.)

NG

Replace

OK

Check the following connectors:
B-06, B-05

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the air outlet changeover damper
motor and the A/C-ECU.

OK

Replace the A/C-ECU.

NG

Repair

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-41

INSPECTION CHART FOR TROUBLE SYMPTOMS

Trouble symptom

Inspection proce-
dure No.

Reference page

Communication with the MUT-

II

 is not possible.

1

55-42

Air conditioner does not operate.

2

55-43

A/C graphic display on control panel is blank.

3

55-44

Temperature cannot be set.

4

55-44

A/C outlet air temperature does not increase.

5

55-44

A/C outlet air temperature does not decrease.

6

55-44

Blower does not operate.

7

55-45

Blower does not operate in HI mode.

8

55-46

Blower air amount cannot be changed.

9

55-47

Air outlet port cannot be changed.

10

55-47

Inside/outside air changeover is not possible.

11

55-48

Defroster function does not operate.

12

55-49

Condenser fan does not operate.

13

55-50

Rear defogger does not operate.

14

55-51

A/C-ECU power supply circuit check

15

55-52

A/C compressor control circuit check

16

55-53

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-42

INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection procedure 1

Communication with the MUT-

II

 is not possible.

Probable cause

If communication with all other systems is not possible, there is a high
possibility that there is a malfunction of the diagnosis line. If communication
with only the A/C is not possible, the cause is probably a malfunction of the
diagnosis line or of the A/C-ECU power supply system (earth).

D

Malfunction of connector or harness

D

Malfunction of A/C-ECU

Is communication between MUT-

II

 and

other system possible?

NO

Check the MUT-

II

 diagnosis line, and

repair if necessary.

YES

Measure at the diagnosis connector
B-22.

D

Voltage between terminal (11)
and body earth
OK: Indication fluctuates be-

tween 0 V and 12 V.

OK

Measure at the A/C-ECU connector
B-04.

D

Disconnect the connector, and
measure at the harness side
connector.

D

Voltage between terminal (18)
and body earth
OK: System voltage – 2 V

NG

Check the following connector:
B-04

OK

Check the trouble symptom.

NG

Repair

NG

Measure at the A/C-ECU connector
B-04.

D

Connect the connector.

D

Voltage between terminal (17)
and body earth
OK: Indication fluctuates be-

tween 0 V and 12 V.

NG

OK

Check the following connector:
B-04

NG

Check the harness between the diagno-
sis connector and the A/C-ECU, and
repair if necessary.

NG

Repair

OK

Check the harness between the diagno-
sis connector and the A/C-ECU.

NG

Repair

OK

Check the trouble symptom.

OK

Check the following connectors:
B-04, B-22

NG

Repair

OK

Check the trouble symptom.

NG

Measure at the A/C-ECU connector
B-05.

D

Disconnect the connector, and
measure at the harness side
connector.

D

Voltage between terminal (28)
and body earth
OK: System voltage

NG

Check the following connectors:
B-49, B-75

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the junc-
tion block and the A/C-ECU, and repair
if necessary.

OK

Measure at the A/C-ECU connector
B-05.

D

Disconnect the connector, and
measure at the harness side
connector.

D

Continuity between terminals
(29), (35) and body earth
OK: Continuity

NG

Check the following connectors:
B-05, B-48, B-19, B-67, B-80

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the
A/C-ECU and the body earth, and repair
if necessary.

OK

Replace the A/C-ECU.

NG

Replace the A/C-ECU.

FULL-AUTOMATIC AIR CONDITIONER – 

Troubleshooting

55-43

Inspection procedure 2

Air conditioner does not operate.

Probable cause

If the A/C does not operate when the A/C switch is on and the temperature
setting is at 17

_

C, the cause is probably insufficient refrigerant, or a

malfunction of the blower or of the magnet clutch power supply.

D

Malfunction of blower

D

Insufficient refrigerant

D

Malfunction of magnetic clutch

D

Malfunction of air thermo sensor

D

Malfunction of A/C compressor relay

D

Malfunction of refrigerant temperature switch

D

Malfunction of dual pressure switch

D

Malfunction of water temperature switch

D

Malfunction of connector or harness

D

Malfunction of engine-ECU

D

Malfunction of A/C-ECU

Does the blower operate?

NO

Inspection procedure 7 (Refer to P.55-45.)

YES

A/C system refrigerant pressure check (Refer to P.55-13.)

NG

Refill the specified amount of refrigerant. (Refer to P.55-6.)

OK

MUT-

II

 Self-Diag code

Is any of the codes 11, 12, 21 and 22 output?

YES

INSPECTION CHART FOR DIAGNOSIS CODES (Refer to
P.55-34.)

NO

D

Magnetic clutch check (Refer to P.55-25.)

D

A/C compressor relay check (Refer to P.55-14.)

D

Refrigerant temperature switch check (Refer to P.55-25.)

D

Dual pressure switch check (Refer to P.55-13.)

D

Water temperature switch check (Refer to P.55-64.)
<2,000>

NG

Replace

OK

Measure at the A/C compressor relay connector A-116X.

D

Disconnect the connector, and measure at the harness
side connector.

(1) Continuity between terminal (4) and body earth

OK: Continuity

(2) Voltage between terminal (5) and body earth

OK: System voltage

OK

Inspection procedure 13 (Refer to P.55-50.)

(2) NG

Check the following connector:
A-116X

(1) NG

Check the following connectors:
A-116X, A-106

NG

Repair

NG

Repair

OK

Check the trouble symptom.

NG

Check the harness between the fusible link and the A/C compressor
relay, and repair if necessary.

OK

Check the trouble symptom.

NG

Check the harness between the magnetic clutch and the A/C
compressor relay, and repair if necessary.