DTC Troubleshooting: U1280
DTC U1280: B-CAN Communication Bus Line Error (BUS-OFF)
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.

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

1.
Problem verification:

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:

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
Gauge control module
Connector A (32P)
Climate control unit
Connector A (32P)
Immobilizer-keyless control unit
7P connector
Power window master switch
37P connector
Automatic lighting/rain sensor
5P connector
Automatic lighting control unit-sensor
5P connector
Audio unit
Connector A (24P)
Audio-navigation unit
Connector A (24P)
Front seat heater control unit
14P connector
Wireless charger
7P connector
Parking and back-up sensor control unit
16P connector

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):

Shorted wire check (B-CAN lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Body control module connector B (36P)

?3.
Check for continuity between test points 1 and 2 individually.
Test condition
Vehicle OFF (LOCK) mode
Body control module connector B (36P): disconnected
Test point 1
Test point 2
Body ground

Test point 1
Test point 2
Body ground

Is there 1 M? or more?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Repair a short to ground in the B-CAN wires.?
4.
Shorted wire check (B-CAN_L to B-CAN_H line):

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
Body control module connector B (36P): disconnected
Test point 1
Test point 2

Is there 1 M? or more?

     
YES
     
     
     
The B-CAN_L to B-CAN_H wire is OK. Replace the body control module.?
     
NO
     
     
     
Repair a short in the B-CAN_L to B-CAN_H wire.?