U1280

DTC Troubleshooting: U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280, U1280

DTC U1280:

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 Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), and then back to ON (II).

3. Wait for at least 6 seconds.

4. Check for DTCs with the HDS.

Is DTC U1280 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition Battery Test and the charging system.�

5. Turn the ignition switch to LOCK (0).

6. 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.









Is DTC U1280 indicated with each individual unit disconnected?

YES -

Leave the connectors disconnected, and go to step 7.

NO -

Go to the input test (or circuit troubleshooting) for the control unit that was disconnected when DTC U1280 did not reset and perform all power and ground input tests. If the tests prove OK, replace that unit.�

- Passenger's MICU input test
- Door multiplex control unit input test Power Window Master Switch Input Test
- Gauge control unit input test Gauge Control Module Input Test
- Immobilizer-keyless control unit input test Immobilizer-Keyless Control Unit Input Test
- Climate control unit power and ground circuit troubleshooting Climate Control Power and Ground Circuit Troubleshooting
- Power seat control unit input test Power Seat Control Unit Input Test/Replacement
- HandsFreeLink control unit input test HandsFreeLink Control Unit Input Test
- AcuraLink control unit input test
- Audio unit input test
- Audio-navigation unit input test
- Navigation display unit

7. Turn the ignition switch to LOCK (0).

8. Disconnect each control unit connector in the table.










9. Disconnect driver's under-dash fuse/relay box connector P (20P).

10. Check for continuity between driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6.





Is there continuity?

YES -

Repair a short in the B-CAN wires.�

NO -

Go to step 11.

11. Check for continuity between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.





Is there continuity?

YES -

Repair a short to ground in the wire(s).�

NO -

Go to step 12.

12. Turn the ignition switch to ON (II).

13. Measure the voltage between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.





Is there voltage?

YES -

Repair a short to power in the wire(s).�

NO -

Faulty driver's MICU, replace the driver's under-dash fuse/relay box, USA models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA models), Canada models Drivers Under-Dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada models).�