Mitsubishi Lancer Evolution IX. Manual - part 540
TROUBLESHOOTING
HEATER, AIR CONDITIONER AND VENTILATION
55-33
COMMENTS ON TROUBLE SYMPTOM
If cool air is not distributed when the A/C switch is on,
the air thermo sensor or the A/C compressor relay
system may be defective.
PROBABLE CAUSES
• Improper amount of refrigerant
• Malfunction of the air thermo sensor
• Malfunction of the dual pressure switch
• Malfunction of the A/C compressor relay
• Malfunction of the A/C refrigerant temperature
switch
• Malfunction of the magnetic clutch
• Malfunction of the manual air conditioner control
panel (A/C-ECU)
• Damaged the wiring harness or connectors
• Malfunction of the engine-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check the rear window defogger and
outside/inside air selection damper control motor
operation.
Q: Do the rear window defogger and outside/inside air
selection damper control motor work normally?
YES :
Go to Step 2.
NO :
Refer to Inspection procedure 9
"Malfunction of the A/C-ECU power supply
system
."
STEP 2. Check the blower motor operation.
Q: Does the blower motor work normally?
YES :
Go to Step 3.
NO :
Refer to Inspection procedure 4 "The blower
does not work
."
STEP 3. Check the A/C compressor.
Check the A/C compressor for compressor oil leaks.
Q: Is the check result satisfactory?
YES :
Go to Step 4.
NO :
Replace the A/C compressor or the
expansion valve.
STEP 4. Connector check: A-36 A/C compressor
connector and C-121 engine-ECU connector
Q: Is the check result normal?
YES :
Go to Step 5.
NO :
Repair the connector.
AC504616AB
Connector: A-36
A-36 (B)
Harness side
AC504617AB
Connector: C-121 <LHD>
C-121 (GR)
Harness side
AC504618AB
Connector: C-121 <RHD>
Harness side
C-121 (GR)