EngineLightCodes
Powertrain code

P2124 Throttle/Pedal Position Sensor "C" Circuit Low

Severity
Fix soon
Typical repair cost
$90–$440
Do it yourself
Possible, easy
Shop time
0.3–1.5 hours

The "C" channel signal is below the lower threshold — usually a short to ground or an open signal wire.

Written from public technical sources and not yet checked by a mechanic. How we write these pages

Symptoms

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

Common causes

  1. Signal shorted to ground Most likely
  2. Signal wire open Possible
  3. Connector pins corroded - high contact resistance Less likely

How to diagnose P2124

  1. Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
  2. Inspect the parts involved: accelerator pedal sensor, pedal sensor wiring.
  3. Work through the causes above from most to least likely, cheapest checks first.
  4. Clear the code and drive a full drive cycle to confirm the repair held.

Reading the code

P
Powertrain
2
Generic (SAE) code
124
Specific fault

Questions drivers ask

Can I drive with code P2124?

Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.

Will my car pass an emissions inspection with P2124?

Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.

Will P2124 clear by itself?

The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.

Can I fix P2124 myself?

Often yes, with an OBD-II scanner and basic tools. Difficulty: easy. Start with the cheapest checks before replacing expensive parts.

This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.