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. Reading and Clearing Diagnostic Trouble Codes

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 Pending or Confirmed 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. Measure the voltage between throttle body 6P connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 20.

NO - Go to step 8.






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

7. Disconnect the throttle body 6P connector.

8. Disconnect the C251 connector (13P) between the PCM subharness and the throttle actuator control module subharness.

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






10. Check for continuity between C251 connector (13P) terminal No. 4 and body ground.

Is there continuity?
YES - Go to step 11.

NO - Repair open in the wire between the throttle body and the C251 connector (TPSA line), then go to step 22.






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

12. Check for continuity between throttle actuator control module 16P connector terminal No. 10 and C251 connector (13P) terminal No. 4.

Is there continuity?
YES - Go to step 27.

NO - Repair open in the wire between the throttle actuator control module and the C251 connector (TPSA line), then go to step 22.






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

14. Disconnect the throttle body 6P connector.

15. Disconnect the C251 connector (13P) between the PCM subharness and the throttle actuator control module subharness.

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






17. Check for continuity between C251 connector (13P) terminal No. 5 and body ground.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wire between the throttle body and the C251 connector (SG line), then go to step 22.






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

19. Check for continuity between throttle actuator control module 16P connector terminal No. 9 and C251 connector (13P) terminal No. 5.

Is there continuity?
YES - Go to step 27.

NO - Repair open in the wire between the throttle actuator control module (SG line) and the C251 connector, then go to step 22.






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

21. Replace the throttle body. Removal and Replacement

22. Reconnect all connectors.

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

24. Reset the PCM with the HDS.

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

26. Check for Pending or Confirmed 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 Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.


27. Reconnect all connectors.

28. Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM. Reading and Clearing Diagnostic Trouble Codes

29. Check for Pending or Confirmed 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. If the PCM was updated, substitute a known-good PCM, Reading and Clearing Diagnostic Trouble Codes then recheck. If the PCM was substituted, go to step 1.

NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. Service and Repair If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.