U0122

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

NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- If DTC U0073 is stored at the same time as DTC U0122, troubleshoot DTC U0073 first, then recheck for DTC U0122.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC U0122 indicated?

YES - Go to step 4.

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

4. Check for DTCs in the DTCs MENU with the HDS.

Is VSA system DTC 86 Indicated?

YES - Go to step 5.

NO - Go to step 8.

5. Turn the ignition switch OFF.
6. Disconnect the VSA modulator-control unit 47P connector.




7. Check for continuity between VSA modulator-control unit 47P connector terminals No 14 and No. 30.

Is there continuity?

YES - Substitute a known-good VSA modulator-control unit, then go to step 15 and recheck. If DTC U0122 is not indicated, replace the original VSA modulator-control unit, then go to step 15.

NO - Repair open in the wire between the VSA modulator-control unit (No. 14 (No. 30)) and the PCM (E15 (E26)), then go to step 15.

8. Check for a poor connection at the VSA modulator-control unit 47P connector.

Are the connection OK?

YES - Go to step 9.

NO - Repair the connection(s), then go to step 16.

9. Turn the ignition switch OFF.
10. If not already done, disconnect the VSA modulator-control unit 47P connector.
11. Turn the ignition switch ON (II).




12. Measure voltage between VSA modulator-control unit 47P connector terminal No. 38 and body ground.

Is there battery voltage?

YES - Go to step 13.

NO - Check the No. 18 (15 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the No. 18 (15 A) fuse and the VSA modulator-control unit, then go to step 15.

13. Turn the ignition switch OFF.




14. Check for continuity between VSA modulator-control unit 47P connector terminal No. 32 and body ground.

Is there continuity?

YES - Substitute a known-good VSA modulator-control unit, then go to step 15 and recheck. If DTC U0122 is not indicated, replace the original VSA modulator-control unit, then go to step 15.

NO - Repair open in the wire between the VSA modulator-control unit and G203, then go to step 15.

15. Reconnect the VSA modulator-control unit 47P connector.
16. Turn the ignition switch ON (II).
17. Reset the PCM with the HDS.
18. Do the PCM idle learn procedure.
19. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC U0122 is indicated, check for poor connections or loose terminals at the gauge assembly, the VSA modulator-control unit, and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.