DTC P0123: Throttle Position (TP) Sensor: Condition
This code indicates TP signal is greater than self-test maximum of 4.79 volt. Possible causes for this fault are:
- TP sensor not seated correctly.
- Faulty TP sensor.
- Open TP or VREF circuit.
- TP circuit shorted to SIG RTN or PWR GND.
- Faulty PCM.
- Attempt To Generate DTC P0122
Turn ignition off. Disconnect TP sensor wiring harness connector. Inspect for damage and repair as necessary. Turn ignition on. Using scan tool, access TP PID on scan tool. If TP PID voltage is 0.17 volt or more, go to step 3). If TP PID voltage is less than 0.17 volt, go to next step. - Check VREF Circuit Voltage
With TP sensor disconnected, turn ignition on. Measure voltage between VREF and SIG RTN terminals at TP sensor wiring harness connector. If reading is 4-6 volts, go to next step. If reading is not 4-6 volts, reconnect sensor and repair open VREF circuit. - Check TP Circuit For Short To Power
Turn ignition off. Leave TP sensor disconnected. Disconnect PCM 104-pin connector. Inspect connector for damage and repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 89 (TP) and test pins No. 71, 90 and 97 (VPWR) at breakout box. If any resistance is less than 10 k/ohms, repair TP circuit short to VREF and repeat QUICK TEST. See TESTS W/CODES - INTRODUCTION article. If each resistance is 10 k/ohms or more, replace PCM and repeat QUICK TEST.