DTC B223B: Control Panel Improperly Assembled: Diagnosis

Required Special Tool: 

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (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, diagnose the CAN bus line 
   CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
   1. Connect scan tool MB991958. 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? 

      • YES:  Go to Step 2.
      • NO:  Repair the CAN bus line. (Refer to DIAGNOSIS ).
        Fig 1: Connecting Special Tool To Data Link Connector

        Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Recheck for diagnostic trouble code. 

   Recheck if the DTC is set.

   1. Erase the DTC.
   2. Turn the ignition switch to "ON" position.
   3. Check if the DTC is set.

      Q: Is the DTC set? 

      • YES:  Go to Step 3.
      • NO:  It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .
3. STEP 3. Check A/C control panel connector C-120 and A/C-ECU connector C-20 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are A/C control panel connector C-120 and A/C-ECU connector C-20 in good condition? 

   • YES:  Go to Step 4.
   • NO:  Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION .
4. STEP 4. Check the wiring harness between A/C-ECU connector C-20 (terminal 9) and A/C control panel connector C-120 (terminal 9). 
   • Check the A/C control panel signal line and ground line for open and short circuit.

     Q: Is the wiring harness between A/C-ECU connector C-20 (terminal 9) and A/C control panel connector C-120 (terminal 9) in good condition? 

     • YES:  Go to Step 5.
     • NO:  Repair the wiring harness.
5. STEP 5. Recheck for diagnostic trouble code. 

   Recheck if the DTC is set.

   1. Erase the DTC.
   2. Turn the ignition switch to "ON" position.
   3. Check if the DTC is set.

      Q: Is the DTC set? 

      • YES:  Replace the A/C control panel. Then go to Step 6.
      • NO:  It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .
6. STEP 6. Recheck for diagnostic trouble code. 

   Recheck if the DTC is set.

   1. Erase the DTC.
   2. Turn the ignition switch to "ON" position.
   3. Check if the DTC is set.

      Q: Is the DTC set? 

      • YES:  Replace the A/C-ECU.
      • NO:  It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .