INSPECTION PROCEDURE 6: Air outlet vent cannot be changed. (Vehicles without A/C): Diagnosis

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

1. STEP 1. Using scan tool MB991958, check for diagnostic trouble code  .

   Check if an heater controller assembly (A/C-ECU) DTC is set.

   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 set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   • YES:  Refer to DIAGNOSTIC TROUBLE CODE CHART  .
   • NO:  Go to Step 2.
     Fig 1: Connecting Special Tool MB991910 To Data Link Connector

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Check mode selection damper control motor connector C-111 and heater controller assembly (A/C-ECU) connector C-61 for loose, corroded or damaged terminals, or terminals pushed back in the connector  .

   Q: Are mode selection damper control motor connector C-111 and heater controller assembly (A/C-ECU) connector C-61 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.
3. STEP 3. Check the wiring harness between heater controller assembly (A/C-ECU) connector C-61 (terminals 28, 21, 23, 22 and 24) and mode selection damper control motor connector C-111 (terminals 3, 2, 5, 4 and 1)  .
   • Check the heater controller assembly (A/C-ECU) signal line for open and short circuit.

   Q: Are the wiring harness between heater controller assembly (A/C-ECU) connector C-61 (terminals 28, 21, 23, 22 and 24) and mode selection damper control motor connector C-111 (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.
4. STEP 4. Replace the mode selection 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 heater controller assembly (A/C-ECU).