Mitsubishi Galant 9G. Manual — part 275

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-176

STEP 7. Check the wiring harness between A/C-ECU
connector C-10 (terminal 8) and the battery.

NOTE: Also check joint connector C-01 and intermediate con-
nector C-29 for loose, corroded, or damaged terminals, or ter-
minals pushed back in the connector. If joint connector C-01 or
intermediate connector C-29 is damaged, repair or replace the
connector as described in GROUP 00E, Harness Connector
Inspection

P.00E-2

.

Q: Is the wiring harness between A/C-ECU connector C-10

(terminal 8) and the battery in good condition?
YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunctions

P.00-14

.

NO : Repair the wiring harness. Check that the air

conditioning works normally.

AC305233AW

CONNECTOR: C-10

HARNESS SIDE

C-10 (B)

AC305232

CONNECTORS: C-01, C-29

C-01

C-29

AS

C-01

C-29

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-177

STEP 8. Measure the resistance at A/C-ECU connector
C-10.
(1) Disconnect A/C-ECU connector C-10, and measure at the

wiring harness side.

(2) Measure the resistance between terminal 2 and ground.

• The measured value should be 2 ohms or less.

Q: Does the measured resistance value correspond with

this range?
YES : Replace the A/C-ECU, and check that the air

conditioning works normally.

NO : Go to Step 9.

STEP 9. Check the wiring harness between A/C-ECU
connector C-10 (terminal 2) and the ground.
Q: Is the wiring harness between A/C-ECU connector C-10

(terminal 2) and ground in good condition?
YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunctions

P.00-14

.

NO : Repair the wiring harness. Check that the air

conditioning works normally.

AC305233AW

CONNECTOR: C-10

HARNESS SIDE

C-10 (B)

AC209364

CONNECTOR C-10
(HARNESS SIDE)

IU

AC305233AW

CONNECTOR: C-10

HARNESS SIDE

C-10 (B)

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-178

SYMPTOM CHART <MIDDLE TYPE>

M1552009900495

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 <MIDDLE TYPE>

INSPECTION PROCEDURE 1: When the Ignition Switch is "ON", the A/C does not Operate.

.

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 compressor

SYMPTOM

INSPECTION
PROCEDURE

REFERENCE
PAGE

When the ignition switch is "ON", the A/C does not operate.

1.

P.55A-178

When the air outlet changeover control knob is moved to DEFROSTER or
DEFROSTER/FOOT position, the A/C or the inside/outside air
changeover damper motor does not operate.

2.

P.55A-179

Outside/Inside air changeover is not possible.

3.

P.55A-180

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

4.

P.55A-186

Blower fan and motor do not turn.

5.

P.55A-204

Blower air amount cannot be changed.

6.

P.55A-216

The A/C indicator flashes.

7.

P.55A-221

Defogger function does not operate.

8.

P.55A-229

Defogger timer function does not operate.

9.

P.55A-241

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

10.

P.55A-242

Condenser fan does not operate.

11.

REFER TO
GROUP 14

−

SYMPTOM
CHART

P.14-3

MANUAL A/C DIAGNOSIS

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-179

DIAGNOSIS

Check that the blower motor operation when the blower
switch is moved to the "HI" position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower speed selection dial to the blower operating

position.

Q: Does the blower motor operate when the speed

selection dial is turned to the blower operating
position?
YES : Refer to Inspection procedure 4 "When the A/C is

operating, temperature inside the passenger
compartment does not decrease (cool air not emitted)

P.55A-186

."

NO : Refer to Inspection procedure 5 "Blower fan and

motor do not turn

P.55A-204

."

INSPECTION PROCEDURE 2: When the Air Outlet Changeover Control Knob is Moved to
DEFROSTER or DEFROSTER/FOOT Position, the A/C or the Inside/outside Air Changeover Damper
Motor does not operate.

.

TECHNICAL DESCRIPTION (COMMENT)

If the outside/inside air selection damper control
motor does not operate normally, the inside/outside
air changeover damper motor system may be defec-
tive.

.

TROUBLESHOOTING HINTS

• Malfunction of the A/C-ECU

• Malfunction of the outside/inside air selection

damper control motor

• Damaged harness wires or connectors

DIAGNOSIS

Check operation of the outside/inside air selection damper
control motor.
(1) Turn the ignition switch to the "ON" position.
(2) Outside/inside air selection damper motor switch: This is

used to switch from the inside air to outside air or vice
versa.

(3) Check to see that the outside/inside air selection damper

motor operates normally.

Q: Does outside/inside air selection damper control motor

work normally?
YES : Replace the A/C-ECU.
NO : Refer to Inspection procedure 3, "Inside/outside air

changeover is not possible

P.55A-180

."