P0120 Throttle/Pedal Position Sensor A Circuit Malfunction
What does P0120 mean?
P0120 — Throttle/Pedal Position Sensor A Circuit Malfunction. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects throttle/pedal position sensor a circuit malfunction. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0120
- Faulty throttle position sensor (TPS)
- Wiring or connector damage in the TPS circuit
- Carbon buildup on throttle plate
- Intermittent connector contact
- PCM fault
How to fix P0120
- Inspect the throttle position sensor wiring and connector
- Watch TPS voltage on an OBD-II scanner while slowly opening the throttle
- Check for a smooth voltage sweep with no drops or spikes
- Clean the throttle body if carbon buildup is present
- Replace the TPS if the voltage sweep is erratic