DTC Troubleshooting

DTC P2123: APP Sensor A (Throttle Position Sensor D) Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Check the APP SENSOR A in the DATA LIST with the HDS.

Is there about 4.9 V or more?

YES - Go to step 3.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the APP sensor and the ECM.

3. Turn the ignition switch OFF.
4. Disconnect the APP sensor 6P connector.
5. Turn the ignition switch ON (II).




6. Measure voltage between APP sensor 6P connector terminals No. 5 and No. 6.

Is there about 5 V?

YES - Go to step 8.

NO - Go to step 7.




7. Measure voltage between ECM connector terminals A20 and A23.

Is there about 5 V?

YES - Repair open in the wire between the ECM (A23) and the APP sensor, then Go to step 10.

NO - Go to step 15.

8. Turn the ignition switch OFF.
9. Replace the APP sensor.
10. Reconnect all connectors.
11. Turn the ignition switch ON (II).
12. Reset the ECM with the HDS.
13. Do the ECM idle learn procedure.
14. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2123 indicated?

YES - Check for poor connections or loose terminals at the APP sensor and the ECM, then Go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, Go to the indicated DTCs troubleshooting.

15. Turn the ignition switch OFF.
16. Reconnect all connectors.
17. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
18. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P2123 indicated?

YES - Check for poor connections or loose terminals at the APP sensor and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, Go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, Go to the indicated DTCs troubleshooting.