U0028

DTC Troubleshooting: U0028 (107)

DTC U0028:

F-CAN Malfunction (PCM receiving failure)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information. How To Troubleshoot The A/T System

1. Clear the DTC with the HDS.

2. Check for Pending or Confirmed DTCs in the PGM-FI SYSTEM with the HDS.

Is DTC U0155 indicated in the PGM-FI SYSTEM?

YES -

Troubleshoot for DTC U0028 in the PGM-FI SYSTEM.�

NO -

Go to step 3.

3. Check for Pending or Confirmed DTCs in the A/T SYSTEM with the HDS.

Is DTC U0028 indicated?

YES -

Go to step 4.

NO -

Intermittent failure, the system is OK at this time.�

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

5. Start the engine in P, and wait for at least 2 minutes.

6. Check for Pending or Confirmed DTCs with the HDS.

Is DTC U0028 indicated?

YES -

Check for poor connections or loose terminals between the PCM and the connections on the F-CAN circuit. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 5. If the PCM was substituted, reinstall the original PCM, then go to step 1.

NO -

Go to step 7.

7. Monitor the OBD STATUS for U0028 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?

YES -

If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 6 U0028, go to the indicated DTC's troubleshooting.�

NO -

If the HDS indicates FAILED, check for poor connections or loose terminals between the PCM and the connectors on the F-CAN circuit. If the PCM was updated, substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 5. If the PCM was substituted, reinstall the original PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 5.