U1280

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

DTC U1280:

Communication Circuit Error (BUS-OFF)

NOTE: If you are troubleshooting multiple DTCs, be sure to follow 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.

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

8. Remove the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal/Installation.

9. Disconnect under-dash fuse/relay box connector T (34P).

10. Check for continuity between under-dash fuse/relay box connector T (34P) terminals No. 12 and No. 29.





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 under-dash fuse/relay box connector T (34P) terminals No. 12 and No. 29 individually.





Is there continuity?

YES -

Repair a short to ground in the B-CAN wire(s).

NO -

Go to step 12.

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

13. Measure the voltage between body ground and under-dash fuse/relay box connector T (34P) terminals No. 12 and No. 29 individually.





Is there voltage?

YES -

Repair a short to power in the B-CAN wire(s).

NO -

Faulty MICU; replace the under-dash fuse/relay box Under-Dash Fuse/Relay Box Removal And Installation.