F-CAN Communication Line Error (Bus-Off)

DTC Troubleshooting: U0029

DTC U0029:

F-CAN Communication Line Error (BUS-OFF)

NOTE:

- Make sure the HDS communicates with the ECM/PCM and other vehicle systems. If it does not, go to DLC Circuit Troubleshooting Testing and Inspection.
- 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 U0029 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the F-CAN communication line is OK at this time. Check for DTCs in the ECM/PCM with the HDS. If F-CAN DTCs are present, check for loose or poor connections at the gauge control module and the ECM/PCM. If the connections are good, check the battery condition and the charging system, then clear all DTCs.�

5. Check for DTCs in the ECM/PCM with the HDS.

Are any DTCs indicated?

YES -

Go to the indicated ECM/PCM DTC's troubleshooting.�

NO -

Go to step 6.

6. Do the gauge control module input test Component Tests and General Diagnostics.

Are all inputs OK?

YES -

Go to step 7.

NO -

Repair the faulty input, then recheck the DTCs.�

7. Substitute a known-good gauge control module.

8. Clear the DTCs with the HDS.

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

10. Start and run the engine for at least 5 seconds, then turn the engine off.

11. Check for DTCs with the HDS.

Is DTC U0029 indicated?

YES -

Go to step 12.

NO -

The original gauge control module is faulty; replace it.�

12. Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM Initial Inspection and Diagnostic Overview.

13. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0029 indicated?

YES -

Check for poor connections or loose terminals at the gauge control module and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM Initial Inspection and Diagnostic Overview, then recheck. If the ECM/PCM was substituted, go to step 1.

NO -

If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.