DTC P0122 - Throttle Position (TP) Sensor: Condition

This code indicates TP signal is less than self-test minimum of 0.17 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.

1)  Turn ignition off. Disconnect TP sensor wiring harness connector. Inspect for damage and repair as necessary. Connect jumper wire between VREF and TP terminals at TP wiring harness connector. Turn ignition on. Access TP PID on scan tool. If PID voltage is more than 4.60 volts, replace TP sensor and repeat QUICK TEST. If PID voltage is 4.60 volts or less, remove jumper wire and go to next step. If scan tool is unable to access TP PID, go to step 4).

2) 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 voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, reconnect sensor and repair open VREF circuit.

3) Check TP Circuit Resistance  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 TP terminal of TP sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in TP circuit.

4) Check TP Circuit For Short To SIG RTN Or PWR GND  Leave ignition off and TP sensor disconnected. Measure resistance between test pin No. 89 (TP) and test pins No. 91 (SIG RTN), 24 and 103 (PWR GND) at breakout box. If any resistance is less than 10,000 ohms, repair TP circuit short to SIG RTN or PWR GND and repeat QUICK TEST. If both resistances are 10,000 ohms or more, replace PCM and repeat QUICK TEST.