With PGM-FI System

DTC Troubleshooting: U0122, U0122

DTC U0122:

F-CAN Malfunction (ECM/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), or press the engine start/stop button to select the ON mode.

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

Are DTC U0029 and U0122 indicated at the same time?

YES -

Go to the troubleshooting for DTC U0029 U0029.�

NO -

Go to step 3.

3. Clear the DTC with the HDS.

4. Check for Pending or Confirmed 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 ECM/PCM.�

5. Check for communication to the VSA system with the HDS.

Does the HDS communicate with the VSA modulator-control unit?

YES -

Go to step 6.

NO -

Go to the symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off ABS Indicator, Brake System Indicator, and VSA Indicator Do Not Go Off.�

6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

7. Jump the SCS line with the HDS.

8. Disconnect the VSA modulator-control unit 47P connector.

9. Disconnect ECM/PCM connector A (49P).

10. Check for continuity between ECM/PCM connector terminal A48 and VSA modulator-control unit 47P connector terminal No. 12.





Is there continuity?

YES -

Go to step 11.

NO -

Repair open in the wire between the ECM/PCM(A48) and the VSA modulator-control unit, then go to step 12.

11. Check for continuity between ECM/PCM connector terminal A49 and VSA modulator-control unit 47P connector terminal No. 13.





Is there continuity?

YES -

Update the VSA modulator-control unit if it does not have the latest software Testing and Inspection, or substitute a known-good VSA modulator-control unit Service and Repair, then go to step 12 and recheck. If DTC U0122 is not indicated after substitution, replace the original VSA modulator-control unit Service and Repair, then go to step 12.

NO -

Repair open in the wire between the ECM/PCM(A49) and the VSA modulator-control unit, then go to step 12.

12. Reconnect all connectors.

13. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

14. Reset the ECM/PCM with the HDS.

15. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure.

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

Is DTC U0122 indicated?

YES -

Check for poor connections or loose terminals at the VSA modulator-control unit and the ECM/PCM, then go to step 1.

NO -

Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.�