DTC U1079: Vehicle Dynamics Control Module Bus Off (Local)

DTC detecting condition: 

VDC Control Module communication is shut down because of high speed CAN error.

Trouble symptom: 

CAN communication is not normal.

1. CHECK CAN COMMUNICATION HARNESS  .

   Perform the basic diagnostic procedure to check for fault in CAN communication harness. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Was the basic diagnostic procedure performed up to step 7?

   Yes:  Go to  2.

   No:  Perform the basic diagnostic procedure. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

2. CHECK DTC  .
   1. Start the engine.
   2. Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC U1079 displayed? (Current code)

   Yes:  Go to  3

   No:  It may be a temporary poor contact. Using the Subaru Select Monitor, perform the clear memory of all DTCs. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY .

3. CHECK CAN COMMUNICATION CIRCUIT  .

   Check CAN communication circuit. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN COMMUNICATION CIRCUIT CHECK>PROCEDURE .

   Is CAN communication circuit faulty?

   Yes:  Repair the faulty portion, following the diagnosis procedure.

   No:  Go to  4.

4. CHECK DTC  .
   1. Perform the inspection using the DTC check sheet. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST > CHECK USING THE DTC CHECK SHEET .
   2. Turn the ignition switch to ON.
   3. Using the Subaru Select Monitor, read DTC of CAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC U1079 displayed? (Current code)

   Yes:  Go to  5

   No:  System is normal.

5. CHECK CONTROL MODULE  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the control modules other than body integrated unit in order.
      NOTE: When disconnecting the control module of end resistance, connect resistance of 120 O between CAN Hi and CAN Lo as an alternative of end resistance.
   3. Turn the ignition switch to ON.
   4. Using the Subaru Select Monitor, read all DTCs. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is there any control module that DTC U1079 is not detected as current code?

   Yes:  Replace the control module that the DTC is not detected as current code.

   No:  Repeat step 5 until DTC U1079 is not detected.