DTC Troubleshooting

DTC Troubleshooting: P0123

DTC P0123: TP Sensor A Circuit High Voltage

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. Clear the DTC with the HDS.

3. Check TP SENSOR A in the DATA LIST with the HDS.

Is there about 4.8 V or more?
YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body and the throttle actuator control module.


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

Are DTC P0123 and P0223 indicated at the same time?
YES - Go to step 13.

NO - Go to step 5.


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

6. Disconnect the throttle body 6P connector.

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

8. Measure the voltage between throttle body 6P connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 18.

NO - Go to step 9.






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

10. Disconnect the throttle actuator control module 16P connector. Service and Repair

11. Connect throttle body 6P connector terminal No. 1 to body ground with a jumper wire.






12. Check for continuity between throttle actuator control module 16P connector terminal No. 10 and body ground.

Is there continuity?
YES - Substitute a known-good throttle actuator control module, Service and Repair then go to step 20 and recheck. If DTC P0123 is not indicated, replace the original throttle actuator control module, Service and Repair then go to step 20. If DTC P0123 is indicated, go to step 18.

NO - Repair open in the wire between the throttle body and the throttle actuator control module (TPSA line), then go to step 20.






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

14. Disconnect the throttle body 6P connector.

15. Disconnect the throttle actuator control module 16P connector. Service and Repair

16. Connect throttle body 6P connector terminal No. 4 to body ground with a jumper wire.






17. Check for continuity between throttle actuator control module 16P connector terminal No. 9 and body ground.

Is there continuity?
YES - Substitute a known-good throttle actuator control module, Service and Repair then go to step 20 and recheck. If DTC P0123 is not indicated, replace the original throttle actuator control module, Service and Repair then go to step 20. If DTC P0123 is indicated, go to step 18.

NO - Repair open in the wire between the throttle body and the throttle actuator control module (SG line), then go to step 20.






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

19. Replace the throttle body. Removal and Replacement

20. Reconnect all connectors.

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

22. Reset the ECM with the HDS.

23. Do the ECM idle learn procedure. ECM Idle Learn Procedure

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

Is DTC P0123 indicated?
YES - Check for poor connections or loose terminals at the throttle body and the throttle actuator control module, 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.