PGM-FI System

DTC Troubleshooting: U0122 (PGM-FI System)

DTC U0122: F-CAN Malfunction (PCM-VSA Modulator-Control Unit)

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

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

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

Are DTC U0028 and U0122 indicated at the same time?
YES - Go to troubleshooting for DTC U0028. U0028

NO - Go to step 3.


3. Clear the DTC with the HDS.

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

Is DTC U0122 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM.


5. Check for communication to the SH-AWD system with the HDS.

Does the HDS communicate with the VSA modulator-control unit?
YES - Go to step 6.

NO - Go to the DLC circuit troubleshooting. Testing and Inspection


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

7. Jump the SCS line with the HDS.

8. Disconnect the VSA modulator-control unit 46P connector. Service and Repair

9. Disconnect PCM connector A (44P).

10. Connect VSA modulator-control unit connector terminal No. 39 to body ground with a jumper wire.






11. Check for continuity between PCM connector terminal A36 and body ground.

Is there continuity?
YES - Go to step 12.

NO - Repair open in the wire between the PCM (A36) and the VSA modulator-control unit, then go to step 14.






12. Connect VSA modulator-control unit connector terminal No. 38 to body ground with a jumper wire.






13. Check for continuity between PCM connector terminal A37 and body ground.

Is there continuity?
YES - Substitute a known-good VSA modulator-control unit, Service and Repair then go to step 14 and recheck. If DTC U0122 is not indicated after substitution, replace the original VSA modulator-control unit, Service and Repair then go to step 14.

NO - Repair open in the wire between the PCM (A37) and the VSA modulator-control unit, then go to step 14.






14. Reconnect all connectors.

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

16. Reset the PCM with the HDS.

17. Do the PCM idle learn procedure. PCM Idle Learn Procedure

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

Is DTC U0122 indicated?
YES - Check for poor connections or loose terminals at the VSA modulator-control unit, and the PCM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.