INSPECTION PROCEDURE 7: A/C Outlet Air Temperature does not Increase: Diagnosis

WARNING: This page is about a different car, the 2015 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe
MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, check for diagnostic trouble code.
Check if an A/C controller assembly (A/C-ECU) DTC is stored.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is stored.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC stored?
- YES: Refer to appropriate DTC table:
  Refer to DIAGNOSTIC TROUBLE CODE TABLE - VEHICLES WITHOUT A/C .
  
  Refer to DIAGNOSTIC TROUBLE CODE TABLE - VEHICLES WITH A/C .
- NO: Go to Step 2.
  
  Fig 1: Connecting Special Tool MB991910 To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Check air mixing damper control motor connector C-118 and A/C controller assembly (A/C-ECU) connector C-60 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are air mixing damper control motor connector C-118 and A/C controller assembly (A/C-ECU) connector C-60 in good condition?
- YES: Go to Step 3.
- NO: Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION . Check that the A/C works normally.
STEP 3. Check the wiring harness between A/C controller assembly (A/C-ECU) connector C-60 (terminals 28, 32, 30, 31 and 29) and air mixing damper control motor connector C-118 (terminals 3, 2, 5, 4 and 1).
- Check the A/C controller assembly (A/C-ECU) signal line for open and short circuit.
Q: Are the wiring harness between A/C controller assembly (A/C-ECU) connector C-60 (terminals 28, 32, 30, 31 and 29) and air mixing damper control motor connector C-118 (terminals 3, 2, 5, 4 and 1) in good condition?
- YES: Go to Step 4.
- NO: Repair the wiring harness. Check that the A/C works normally.
STEP 4. Replace the air mixing damper control motor and check the trouble symptom again
Check the trouble symptom again.

Q: Is the check result satisfactory?
- YES: The procedure is complete.
- NO: Replace the A/C controller assembly (A/C-ECU).