Mitsubishi Outlander GS45X. Manual - part 1009

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-63

SYMPTOM CHART

M1552009900730

CAUTION

During diagnosis, a DTC code associated with 
other system may be set when the ignition switch 
is turned on with connector(s) disconnected. On 
completion, confirm all systems for DTC code(s). 
If DTC code(s) are set, erase them all.

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: When the A/C is Operation, Temperature Inside the Passenger 
Compartment does not Decrease (Cool Air is not Emitted).

.

TECHNICAL DESCRIPTION (COMMENT)

The blower system or the compressor system may 
be defective if there is no cool air coming from the 
vents.

.

TROUBLESHOOTING HINTS

• Malfunction of blower motor

• Malfunction of A/C-ECU

• Malfunction of A/C compressor

SYMPTOM

INSPECTION 
PROCEDURE

REFERENCE 
PAGE

When the A/C is operating, temperature inside the passenger 
compartment does not decrease (cool air is not emitted).

1

P.55A-63

Malfunction of the A/C-ECU power supply system.

2

P.55A-65

The compressor dose not work.

3

P.55A-69

Blower fan and motor do not turn.

4

P.55A-77

Blower air amount cannot be changed.

5

P.55A-82

Outside/Inside air changeover is not possible.

6

P.55A-85

A/C outlet air temperature does not increase.

7

P.55A-87

Air outlet vent cannot be changed.

8

P.55A-89

Rear window defogger function does not operate.

10

P.55A-91

Blower motor power supply system.

11

P.55A-98

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-64

DIAGNOSIS

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
Check if an A/C-ECU DTC is set.
(1) Connect scan tool MB991958. Refer to "How to connect the 

Scan Tool (M.U.T.-III) 

P.42C-7

."

(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?

YES : Refer to Diagnostic Trouble Code Chart 

P.55A-11

.

NO :  Go to Step 2.

STEP 2. Check that the blower motor operation when the 
blower knob is moved to the "Maximum air volume" 
position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower knob to the "Maximum air volume" position
Q: Does the blower motor operate when the blower knob is 

moved to the "Maximum air volume" position?
YES : Go to Step 3.
NO :  Refer to Inspection procedure 4 "Blower fan and 

motor do not turn 

P.55A-77

."

STEP 3. Check the rear window defogger and 
outside/inside air selection damper control motor 
operation.
(1) Turn the ignition switch to the "ON" position.
(2) Check the operations of rear window defogger and 

outside/inside air selection damper control motor.

Q: Do the defogger and outside/inside air selection damper 

control motor work normally?
YES : Refer to Inspection procedure 3 "The A/C compressor 

does not Work 

P.55A-69

."

NO :  Refer to Inspection procedure 2, "Malfunction of the 

A/C-ECU power supply system 

P.55A-65

."

ZC501967

AC404789

AC701411AB

MB991824

MB991827

MB991910

Data link 
connector

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-65

INSPECTION PROCEDURE 2: Malfunction of the A/C-ECU Power Supply System.

.

IG1 
RELAY

AC702632

A/C-ECU

34

FUSIBLE 
LINK

36

AB

A/C-ECU Power Supply Circuit

IGNITION SWITCH (IG1)

RELAY 
BOX

POWER 
SOURCE

FUSIBLE
LINK

POWER 
SOURCE

ETACS-
ECU

AC701632 AI

Connectors: C-307, C-309, C-317

C-307 (B)

C-309 (B)

C-317

AC702208AH

Connector: C-109

C-109 (B)

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-66

TECHNICAL DESCRIPTION (COMMENT)

The A/C-ECU power system may be defective if the 
air conditioning, defogger, and outside/inside air 
selection damper motor all do not operate normally.

.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Damaged harness wires or connectors

DIAGNOSIS

Required Special Tool:

• MB991223: Test Harness Set

STEP 1. Check A/C-ECU connector C-109 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q:  Is A/C-ECU connector C-109 in good condition?

YES : Go to Step 2.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the A/C works normally.

STEP 2. Measure the voltage at A/C-ECU connector C-109. 
(1) Disconnect A/C-ECU connector C-109 and measure the 

voltage at the harness side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 15 and ground.

• The measured value should be approximately 12 volts 

(battery positive voltage).

Q: Is the measured voltage approximately 12 volts?

YES :  Go to Step 5.
NO :   Go to Step 3.

STEP 3. Check ETACS-ECU connector C-317 for loose, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q:  Is ETACS-ECU connector C-317 in good condition?

YES : Go to Step 4.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the A/C works normally.

AC608254 BT

Harness side: C-109