Diagnostic Procedure

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line
CAUTION: To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
1. Connect scan tool (M.U.T.-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
1. YES: Go to Step 2.
2. NO: Repair the CAN bus line (Refer to DIAGNOSIS ).
STEP 2. Using scan tool (M.U.T.-III), DTC check.
Check whether the A/C stores a diagnostic trouble code or not.

Q: Is the check result normal?
1. YES: Go to Step 3.
2. NO: Refer to DIAGNOSTIC TROUBLE CODE CHART .
STEP 3. Voltage measurement at A/C compressor assembly connector.
1. Disconnect the connector, and measure at the wiring harness side.
2. Turn the ignition switch to the "ON" position.
3. Disconnect ECM connector and ground terminal 102.
4. Voltage between terminal 1 and body ground.
  OK: System voltage
Q: Is the check result normal?
1. YES: Go to Step 4.
2. NO: Go to Step 8.
STEP 4. Check the A/C compressor.
Refer to CHECK THE MAGNETIC CLUTCH FOR A/C COMPRESSOR .

Q: Is the check result normal?
1. YES: Go to Step 5.
2. NO: Replace the A/C compressor.
STEP 5. Check the refrigerant temperature switch.
Refer to A/C REFRIGERANT TEMPERATURE SWITCH .

Q: Is the refrigerant temperature switch operating properly?
1. YES: Go to Step 6.
2. NO: Replace the refrigerant temperature switch.
STEP 6. Check the refrigerant level.
Refer to REFRIGERANT LEVEL CHECK, DRAINING AND CHARGING .

Q: Is the refrigerant level correct?
1. YES: Go to Step 7.
2. NO: Correct the refrigerant level (Refer to ON-VEHICLE SERVICE ).
STEP 7. Replace the A/C-ECU, and then recheck the trouble symptom
Check that the compressor works normally.

Q: Is the check result normal?
1. YES: This diagnosis is complete.
2. NO: Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) for 2.4L , OR ENGINE CONTROL MODULE (ECM) for 3.0L ).
STEP 8. Check the A/C compressor relay
Refer to A/C COMPRESSOR RELAY CONTINUITY CHECK .

Q: Is the check result normal?
1. YES: Go to Step 9.
2. NO: Replace the A/C compressor relay.
STEP 9. Voltage measurement at A/C compressor relay connector.
1. Remove the relay, and measure at the relay block side.
2. Voltage between terminal 1, 4 and body ground.
  OK: System voltage
Q: Is the check result normal?
1. YES: Go to Step 11.
2. NO: Go to Step 10.
STEP 10. Check of open circuit in A/C compressor relay power supply line between fusible link and A/C compressor relay connector.
Q: Is the check result normal?
1. YES: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO: Repair the connector(s) or wiring harness.
STEP 11. Check of open circuit in A/C compressor relay power supply line between A/C compressor relay connector and A/C compressor assembly connector.
Q: Is the check result normal?
1. YES: Go to Step 12.
2. NO: Repair the connector(s) or wiring harness.
STEP 12. Check of open circuit in AC/R line (ECM) between A/C compressor relay connector and ECM connector.
Q: Is the check result normal?
1. YES: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO: Repair the connector(s) or wiring harness.