DTC U1280 (Telematics Control Unit)

DTC U1280  : Communication Bus Line Error (a bus OFF state is detected by Telematics-ECU)

DTC (Telematics System)

NOTE: 

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
• Check the connectors for poor connections or loose terminals.

1. MICU DTC check

   -1. Check for MICU DTCs with the HDS.

   DTC Description	DTC
   U1280 Communication bus line error (BUS-OFF)

   Is DTC U1280 indicated?

   YES 

   Go to MICU DTC U1280 troubleshooting .

   NO 

   Go to step 2.

2. Problem verification

   -1. Check for DTCs without the HDS .

   Is DTC U1280 indicated?

   YES 

   The failure is duplicated, go to step 3.

   NO 

   Intermittent failure, the system is OK at this time.

3. Open wire check (B CAN-H line, B CAN-L line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connectors.

   Telematics control unit connector A (36P)

   Driver's under-dash fuse/relay box connector G (16P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Telematics control unit connector A (36P): disconnected
   	Driver's under-dash fuse/relay box connector G (16P): disconnected
   Test circuit	B CAN-H
   Test point 1	Telematics control unit connector A (36P) No. 33 (RED)
   Test point 2	Driver's under-dash fuse/relay box connector G (16P) No. 2 (RED)

   Test circuit	B CAN-L
   Test point 1	Telematics control unit connector A (36P) No. 34 (WHT)
   Test point 2	Driver's under-dash fuse/relay box connector G (16P) No. 1 (WHT)

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Replace the telematics control unit .

   NO 

   Repair an open in the wire (s) between the telematics control unit and the driver's under-dash fuse/relay box.