## DTC Troubleshooting: U0122 (126)

DTC U0122: | F-CAN Malfunction (VSA-ECM)

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

2. | Clear the DTC with the HDS.

3. | Start the engine.

4. | Check for Temporary DTCs or DTCs with the HDS. Is DTC U0122 indicated? YES - Go to 5. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit or the ECM.n

5. | Turn the ignition switch OFF, and wait 10 seconds.

6. | Disconnect the ECM connector No. 4 (40P) and VSA modulator-control unit 46P connector.

7. | Connect the ECM test harness and the test pin box between the ECM and connector.

8. | Connect the VSA modulator-control unit 46P connector terminal No. 39 to body ground with a jumper wire.

9. | Check for continuity between test pin box terminal No. 121 and body ground. Is there continuity? YES - Go to 10. NO - Repair open in the wire between the ECM connector No. 4 terminal No. 40 (test pin box terminal No. 121), and the VSA modulator-control unit connector, then go to 12.

10. | Connect the VSA modulator-control unit 46P connector terminal No. 38 to body ground with a jumper wire.

11. | Check for continuity between test pin box terminal No. 111 and body ground. Is there continuity? YES - Substitute a known good VSA modulator-control unit, and the yawrate/lateral acceleration sensor one at a time until the DTCs are no longer present, then replace the control module that made the DTCs go away. If the symptom does not go away, substitute a known good ECM, then go to 12. NO - Repair open in the wire between ECM connector No. 4 terminal No. 30 (test pin box terminal No. 111), and the VSA modulator-control unit connector, then go to 12.

12. | Turn the ignition switch OFF, and wait 10 seconds.

13. | Reconnect all connectors.

14. | Turn the ignition switch ON (II).

15. | Reset the ECM with the HDS.

16. | Do the ETCS learn procedure.

17. | 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 and loose terminals at the VSA modulator-control unit and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Troubleshooting is complete. If the ECM was substituted, replace the original ECM.n