P0124: Throttle/Pedal Position Sensor/Switch "A" Circuit Intermittent

P0124 means Throttle/Pedal Position Sensor/Switch "A" Circuit Intermittent. The throttle position sensor (sensor "A") reports how far the throttle is open. On electronic throttle (drive-by-wire) systems, two or more sensors cross-check each other. The signal drops out or jumps erratically. Intermittent faults are most often caused by loose or corroded connectors and chafed wiring rather than the sensor itself.

CodeP0124
SystemThrottle control
SeverityHigh
TypeGeneric powertrain

Can I keep driving? Limit driving and diagnose promptly. Continued driving can cause damage, stalling or limp mode.

Common symptoms

  • Check engine light and possibly the electronic throttle warning light
  • Reduced power / limp mode
  • Hesitation, surging or erratic idle
  • Stalling
  • Poor shift quality on automatic transmissions

Possible causes

  • Failed throttle position sensor or throttle body
  • Damaged connector, often from water or heat
  • Wiring fault in the 5 V reference, ground or signal
  • Accelerator pedal position sensor fault (on drive-by-wire)

How to diagnose P0124

  1. Check the sensor reading while slowly opening the throttle: it should rise smoothly with no dropouts.
  2. On drive-by-wire, compare both sensor signals.
  3. Check the connector and the 5 V reference.
  4. After throttle body work, perform the manufacturer's throttle relearn procedure.

What the code means, digit by digit

PPowertrain0Generic (SAE) code1Sub-system24Specific fault

Generic codes have the same definition on every OBD-II vehicle (petrol cars from model year 1996 in the US, 2001 in the EU; diesels later). Manufacturers can add their own enhanced codes; those are not listed here.

Related codes

General guidance only. Fault codes describe what the engine computer saw, not which part failed: confirm with testing before replacing parts, and follow the vehicle's service information.