A/T System

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 the General Troubleshooting Information How to Troubleshoot the A/T System.

1. Clear the DTC with the HDS.

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

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

Is DTC U0028 indicated in the PGM-FI SYSTEM?

YES -

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

NO -

Go to step 4.

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

Is DTC U0028 indicated in the A/T SYSTEM?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time.

5. Update the A/T software in the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.

6. Start the engine in P, and let it idle for 2 minutes.

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

Is DTC U0028 indicated in the A/T SYSTEM?

YES -

If the PCM was updated, substitute a known-good PCM, then go to step 6. If the PCM was substituted, go to step 1.

NO -

Go to step 8.

8. 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 7, go to the indicated DTC's troubleshooting.

NO -

If the HDS indicates FAILED, check for poor connections or loose terminals at the PCM and the connectors on the F-CAN circuit. If the PCM was updated, substitute a known-good PCM, then go to step 6. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, go to step 6.