P0122: Throttle/Pedal Position Sensor A Circuit Low

Common causes

• A faulty throttle position sensor
• An open or shorted wire to the sensor
• A loose or corroded connector
• A failing electronic throttle body on drive-by-wire vehicles

Code meanings can vary slightly by manufacturer. Use these as a starting point and confirm with your vehicle's service information or a mechanic before replacing parts.

Symptoms

• Check engine light, sometimes a reduced-power warning
• Hesitation, surging or stalling
• Poor idle
• Limited throttle response (limp mode)

Is it safe to drive?

Drive with care. If the car goes into reduced-power or limp mode it may not accelerate normally, which can be unsafe in traffic.

How to check it with a scanner

1. Plug an OBD2 scanner into the port under the dashboard and read all stored codes and the freeze-frame data (the conditions when the code set).
2. Inspect the throttle body connector and wiring.
3. Watch the TPS reading in live data as you slowly press the pedal with the engine off and key on. It should rise smoothly with no drops or jumps.
4. On electronic throttle systems, the sensor is usually part of the throttle body.
5. After a repair, clear the code and drive normally for a few days to confirm it doesn't come back.

A basic code reader shows the code; scanners with live data let you watch sensor readings, which is what you need for most of the checks above. See OBD2 scanners under $100.

Questions

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