DTC B2402: STL unit comm. (system ID),; DTC B2403: STL unit comm. (CRC),; DTC B2404: STL unit comm. (function code),; DTC B2405: STL unit comm. (rolling code),; DTC B2406: STL unit comm. (PTC operate),; DTC B2407: STL unit comm. (EEPROM),; DTC B2408: STL unit comm. (solenoid): Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicles Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

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 to the data link connector.
   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 ).
         Fig 1: Connecting Scan Tool To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Check key reminder switch connector C-211 and KOS-ECU connector C-102 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is the key reminder switch connector C-211 and KOS-ECU connector C-102 in good condition? 

   1. YES:  Go to Step 3.
   2. NO:  Repair the defective connector.
3. STEP 3. Check the wiring harness between the key reminder switch connector C-211 (terminal No. 12, 9) and the KOS-ECU connector C-102 (terminal No. 4, 5). 
   • Check the signal lines for open circuit and short circuit.

     Q: Is the wiring harness between key reminder switch connector C-211 (terminal No. 12, 9) and the KOS-ECU connector C-102 (terminal No. 4, 5) in good condition? 

     1. YES:  Go to Step 4.
     2. NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
4. STEP 4. Replace the key reminder switch, and check whether the diagnostic trouble code is reset. 
   1. Erase the DTC.
   2. Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
   3. Check if the DTC is set.

      Q: Is the DTC set? 

      1. YES:  Replace KOS-ECU and register the ID codes. (Refer to ID CODES REGISTRATION JUDGMENT TABLE  .
      2. NO:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).