INSPECTION PROCEDURE 1: Communication Between Scan Tool (M.U.T.-IIISE) and AWC-ECU Cannot be Established: Diagnosis

Required Special Tools: 

• MB992006: Extra fine probe

1. STEP 1. Scan tool (M.U.T.-IIISE) CAN bus diagnostics 

   Use scan tool (M.U.T.-IIISE) to diagnose the CAN bus lines.

   Q: Is the check result normal? 

   YES:  Go to Step  2.

   NO:  Repair the CAN bus line (Refer to CAN BUS DIAGNOSTICS TABLE ).

2. STEP 2. Voltage measurement at the AWC-ECU connector 
   1. Disconnect the AWC-ECU connector.
   2. Turn the ignition switch to the ON position.
   3. Measure the voltage between the AWC-ECU wiring harness side connector terminals AWDF, IG16 (Ignition switch "ON") and the body ground.

      OK: System voltage 

   Q: Is the check result normal? 

   YES:  Go to Step  3.

   NO:  Repair the connector(s) or terminal(s) or wiring harness.

3. STEP 3. Resistance measurement at the AWC-ECU connector 
   1. Disconnect the AWC-ECU connector.
   2. Measure the resistance between the AWC-ECU wiring harness side connector terminal GND1 and the body ground.

      OK: Continuity exists (2 Ω or less) 

   Q: Is the check result normal? 

   YES:  Go to Step  4.

   NO:  Repair the connector(s) or terminal(s) or wiring harness.

4. STEP 4. Retest the system  .

   Q: Does the malfunction occur again? 

   YES:  Replace AWC-ECU (Refer to AWC-ECU <AWD>  ).

   NO:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).