DTC U1280 (MICU (Multiplex Integrated Control Unit)) (2016 2017)

DTC U1280  : B-CAN Communication Bus Line Error (BUS-OFF)

DTC (MICU)

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

1. Problem verification

   -1. Clear the DTCs with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   -3. Wait for at least 6 seconds.

   -4. Check for DTCs with the HDS.

   DTC Description	DTC
   U1280 B-CAN Communication Bus Line Error (BUS-OFF)

   Is DTC U1280 indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. B CAN related units check

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

   -2. Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.

   Control Unit	Connector
   Relay control module	Connector B (16P)
   Gauge control module	Connector A (32P)
   Climate control unit	Connector A (28P)
   Power window master switch	37P connector
   Headlight leveling control unit	12P connector
   Automatic lighting/rain sensor	5P connector
   Windshield wiper control unit	6P connector
   Keyless access/TPMS control unit*1	Connector C (20P)
   Keyless access control unit*2	Connector B (28P)
   Parking and back-up sensor control unit	24P connector
   Power seat control unit	Connector A (20P)
   Audio-navigation unit	Connector A (24P)
   Telematics control unit	36P connector
   Left side BSI radar unit	6P connector
   Right side BSI radar unit	6P connector

   *1: USA and Canada models

   *2: Mexico models

   DTC Description	DTC
   U1280 B-CAN Communication Bus Line Error (BUS-OFF)

   Is DTC U1280 indicated with each individual unit disconnected?

   YES 

   Leave the connectors disconnected, and go to step 3.

   NO 

   Replace the control unit that was disconnected when DTC U1280 did not reset.

3. Shorted wire check (B-CAN lines)

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

   -2. Disconnect the following connector.

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

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

   Test condition	Vehicle OFF (LOCK) mode Driver's under-dash fuse/relay box connector G (16P): disconnected
   Test circuit	B-CAN_L
   Test point 1	Driver's under-dash fuse/relay box connector G (16P) No. 1 (WHT)
   Test point 2	Body ground

   Test circuit	B-CAN_H
   Test point 1	Driver's under-dash fuse/relay box connector G (16P) No. 2 (RED)
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair a short to ground in the B-CAN wires.

   NO 

   Go to step 4.

4. Shorted wire check (B-CAN_L to B-CAN_H line)

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

   Test condition	Vehicle OFF (LOCK) mode Driver's under-dash fuse/relay box connector G (16P): disconnected
   Test circuit	B-CAN_L, B-CAN_H
   Test point 1	Driver's under-dash fuse/relay box connector G (16P) No. 1 (WHT)
   Test point 2	Driver's under-dash fuse/relay box connector G (16P) No. 2 (RED)

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

   Is there continuity?

   YES 

   Repair a short in the B-CAN_L to B-CAN_H wire.

   NO 

   The B-CAN_L to B-CAN_H wire is OK. Faulty MICU; replace the driver's under-dash fuse/relay box .