OBD-II code · Powertrain (generic)

P0122 Throttle/Pedal Position Sensor "A" Low Input

The TPS signal voltage is below the lower acceptable threshold. The ECU usually enters limp-home mode and limits engine torque while the fault is active.

Is it safe to drive with P0122?

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

Common causes

  • Most likelySignal wire shorted to ground
  • PossibleTPS internally failed
  • Less likely5V reference voltage to TPS missing

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.