LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2021 >> ILX >> Repair and Diagnosis >> External Pages >> Different car >> Section 40 (Body Control Module - Diagnostics (Except Hybrid)) >> DTC Troubleshooting >> DTC U1280 (Body Control Module)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U1280 (Body Control Module)

WARNING: This page is about a different car, the 2022 Honda Accord, 2021 Honda Accord, 2020 Honda Accord, 2019 Honda Accord, and 2018 Honda Accord. However, it is still accessible from the selected car via links, so may be relevant.

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)  

DTC (Body Control Module)

  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
    Gauge control module Connector A (32P)
    Climate control unit Connector A (32P)
    Relay control module Connector C (18P)
    Power window master switch 37P connector
    Automatic lighting control unit-sensor 5P connector
    Power seat control unit Connector A (20P)
    Front seat heater control unit 24P connector
    Ventilated seat control unit 24P connector
    Telematics control unit Connector A (32P)
    Audio unit Connector A (24P)
    Audio-navigation unit Connector A (24P)
    Left side BSI radar unit 6P connector
    Right side BSI radar unit 6P connector
    Head Up Display 20P connector
    Wireless charger 7P 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)

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

    -2. Disconnect the following connector.

    Body control module connector A (66P)

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

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector A (66P): disconnected
    Test point 1 Body control module connector A (66P) No. 54
    Test point 2 Body ground
    Test point 1 Body control module connector A (66P) No. 55
    Test point 2 Body ground

    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
    Body control module connector A (66P): disconnected
    Test point 1 Body control module connector A (66P) No. 54
    Test point 2 Body control module connector A (66P) No. 55

    Is there continuity?

    YES 

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

    NO 

    The B-CAN_L and B-CAN_H wire are OK. Replace the body control module .