Mitsubishi Grandis. Manual - part 312

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-133

Step 9. Connector check: C-215 rear blower 
motor connector

Q: Is the check result normal?

YES : 

Go to Step 10.

NO : 

Repair the connector.

STEP 10. Check the rear blower relay

 Refer to 

P.55-196

.

Q: Is the check result normal?

YES : 

Refer to Inspection Procedure 22: Rear 

blower motor power supply system 
<LHD>

P.55-152

  or Inspection Procedure 

23: Rear blower motor power supply system 
<RHD>

P.55-160

 .

NO : 

Replace the rear blower relay.

AC310623

Connector: C-215 <LHD>

AH

Junction block side

Junction block (Front view)

AC310618

Connector: C-215 <RHD>

AH

Junction block side

Junction block (Front view)

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-134

INSPECTION PROCEDURE 16: Air volume of rear blower cannot be changed

COMMENTS ON TROUBLE SYMPTOM

If the blower air volume can not be changed when 
the blower switch is operated, the wiring harness 
between A/C-ECU and rear heater controller, and 
rear power transistor circuit system may be 
defective.

POSSIBLE CAUSES

• Malfunction of rear power transistor 

• Malfunction of the A/C-ECU

• Damaged harness wires and connectors

Step 1. MUT-III diagnosis code

Check whether the air conditioner sets a diagnosis 
code or not.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Refer to diagnosis code chart 

P.55-8

.

Step 2. MUT-III actuator test

Carry out the actuator test. (Refer to 

P.55-186

.)

• Item 04: Rear Blower fan: OFF

• Item 05: Rear Blower fan: AUTO <vehicles with 

dual automatic A/C>

• Item 06: Rear Blower fan: Lo

• Item 07: Rear Blower fan: Middle

• Item 08: Rear Blower fan: High

Q: Does the blower motor work normally?

YES : 

Go to Step 3.

NO : 

Go to Step 4.

REAR
BLOWER
RELAY

REAR POWER
TRANSISTOR

REAR BLOWER
MOTOR

A/C-ECU

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

Rear Blower Motor Circuit

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-135

Step 3. MUT-III data list

Check that the following service data display 
contents are normal. (Refer to 

P.55-183

.)

• Item 22: Rear blower motor

• Item 23: Rear blower motor (target value)

• Item 32: Rear control OFF SW

• Item 33: Rear control FAN SW

Q: Is the check result normal?

YES : 

Go to Step 10.

NO : 

Refer to Inspection Procedure 14: Rear 
blower does not work <Vehicle with rear 
heater or rear cooler>

P.55-120

  or 

Inspection Procedure 15: Rear blower does 
not work <Vehicle with rear heater or rear 
cooler>

P.55-127

Step 4. Connector check: D-11 rear power 
transistor connector

Q:  Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the connector.

Step 5. Resistance measurement at D-11 rear 
power transistor connector.

(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Continuity between terminal 2 and body earth.

OK: 2 ohm or less

Q: Is the check result normal?

YES : 

 Go to Step 7.

NO : 

 Go to Step 6.

Step 6. Check the wiring harness between D-11 
rear power transistor connector terminal No.2 
and earth.

• Check the rear window defogger earth line for 

open or short 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 or replace the wiring harness.

AC310207

AC

Harness side

Connector: D-11

AC310207

AC

Harness side

Connector: D-11

AC310506

Connector D-11 
(Harness side)

AT

AC310207

AC

Harness side

Connector: D-11

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-136

Step 7. Connector check: C-104 A/C-ECU 
connector

Q:  Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the connector.

AC310613

AK

Connector: C-104 <LHD>

Harness side

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AC310631AH

Connector: C-104 <RHD>

Harness side

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