Mitsubishi Colt Ralliart. Manual - part 663

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-13

Step 2. M.U.T.-III data list.
Check that the following service data display con-
tents are normal. (Refer to 

P.55B-24

).

• Item 06: 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 

P.00-13

).

NO : 

Replace the combination meter (meter and 
A/C-ECU).

Step 4. Connector check: B-13 photo sensor 
connector and B-15 combination meter 
connector 

AC313823 AM

Connectors: B-13, B-15

Harness side

B-15 (B)

B-15

B-13 (B)

B-13

Q:  Is the check result normal?

YES : 

 Go to Step 5.

NO : 

Repair the connector.

Step 5. Check the wiring harness between B-13 
photo sensor connector (terminal 1 and 2) and 
B-15 combination meter connector (terminal 14 
and 6).

AC313823 AM

Connectors: B-13, B-15

Harness side

B-15 (B)

B-15

B-13 (B)

B-13

• Check the A/C compressor relay power supply 

line for open circuit.

Q: Is the check result normal?

YES : 

 Go to Step 6.

NO : 

Repair the wiring harness. Check that the 
air conditioner works normally.

Step 6. Replace the photo sensor and recheck 
the trouble symptom
 Check that the air conditioner works normally.

Q: Is the check result normal?

YES : 

This diagnosis is complete.

NO : 

Replace the combination meter (meter and 
A/C-ECU).

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Index

Group

TOC

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-14

Inspection Procedure 2: The blower does not work

FUSIBLE
LINK

6

IGNITION
SWITCH (IG2)

BLOWER
RELAY

COMBINATION
METER

METER AND A/C-ECU

BLOWER MOTOR
DRIVE CIRCUIT

BLOWER
MOTOR

POWER
TRANSISTER

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Gray     R : Red     P : Pink     V : Violet

Blower Motor Circuit

COMMENTS ON TROUBLE SYMPTOM

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

POSSIBLE CAUSES

• Malfunction of the blower motor.

• Malfunction of the power transistor.

• Malfunction of the combination meter (meter and 

A/C-ECU)

• Damaged the wiring harness or connectors

Main

Index

Group

TOC

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-15

DIAGNOSIS PROCEDURE

Step 1. M.U.T.-III actuator test
Carry out the actuator test. (Refer to 

P.55B-25

)

• Item 01, 02, 03: blower fan

Q: Does the blower motor work normally? 

YES : 

Go to Step 2.

NO : 

Go to Step 3.

Step 2. Recheck the trouble symptom

Q: Is the check result normal?

YES : 

Intermittent malfunction (GROUP 00 

− How 

to Cope with Intermittent Malfunction 

P.00-13

).

NO : 

Go to Step 19.

Step 3. Connector check: B-116 blower relay 
connector

AC313824

Connector: B-116

AD

Junction block side

Junction block (Front view)

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the connector.

Step 4. Check the blower relay.
Refer to GROUP 55A, On-vehicle Service 

− Power 

relay check 

P.55A-52

.

Q: Is the blower relay in good condition?

YES : 

Go to Step 5.

NO : 

Replace the blower relay.

Step 5. Connector check: B-10 blower motor 
connector and B-15 combination meter 
connector

AC313823AN

Connectors: B-10, B-15

Harness side

B-15 (B)

B-15

B-10

B-10

Harness side

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the connector.

Main

Index

Group

TOC

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-16

Step 6. Voltage measurement at the B-10 blower 
motor controller connector.

AC313822

Connector: B-10

AK

Harness side

(1) Disconnect the connector, and measure at the 

wiring harness side.

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

AC313822 AB

Connector: B-15

Harness side

B-15 (B)

AC309471

AC309471AM

Connector B-15 
(Harness side)

(3) Disconnect combination meter connector B-15, 

and earth terminal 12.

AC310507

Connector B-10 
(Harness side)

FH

(4) measure the voltage between terminal 1 and 

body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 13.

NO : 

Go to Step 7.

Step 7. Voltage measurement at B-116 blower 
relay connector.

AC313824

Connector: B-116

AD

Junction block side

Junction block (Front view)

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

block side.

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

AC310507 EI

Connector C-116 
(Junction block side)

(3) Voltage between terminal 1 and body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Go to Step 8.

Main

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