P2123: Throttle/Pedal Position Sensor/Switch D Circuit High
Do not keep driving
Expect no throttle response or a hard power restriction. Have the pedal connector inspected before the pedal assembly is replaced.
What this code means
Sensor D reads above its valid range — an open circuit or a short to supply. The module refuses it for the same reason it refuses an implausibly low reading: a pedal signal it cannot trust is worse than no pedal signal, because the failure would be in the direction of unrequested power.
An open circuit is the more common of the two here, and a corroded connector produces it just as effectively as a broken wire.
Likely causes
Start here
- Open circuit in sensor wiring · moderate
- Corroded accelerator pedal connector · easy
- Faulty accelerator pedal position sensor · easy
Less common
- Wiring shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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