OBD-II code · Powertrain (generic)

P0123 Throttle/Pedal Position Sensor "A" High Input

The TPS signal voltage exceeds the upper acceptable threshold. As with P0122, limp-home mode is typical until the fault clears.

Is it safe to drive with P0123?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelySignal wire shorted to supply voltage
  • PossibleSensor ground broken
  • Less likelyTPS internally failed

Symptoms

  • Check engine light on
  • Reduced throttle response, possible limp mode
  • Hesitation or surging
  • Idle too high or too low

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Throttle Position Sensor, Throttle Position Sensor Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.