What does code P2122 mean?

P2122 means pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking. It’s serious — diagnose it promptly to avoid expensive damage.

What does P2122 mean in plain words?

Pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking. Expect reduced-power mode; inspect the pedal connector and harness in the footwell before replacing the pedal assembly.

Can I just clear it and drive?

It returns — pedal plausibility is checked continuously. Clearing is for confirming a repair, not living with one missing.

Pedal assembly or throttle body — which am I buying?

P2122–P2128 = pedal-side sensors (the pedal assembly). P0120-family and P2135 = throttle-body-side. The code prefix decides which end of the wire you're shopping for.

P2122 — Accelerator Pedal Position Sensor D Circuit Low

Severe

Quick answer

P2122 means pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking. First move: expect reduced-power mode; inspect the pedal connector and harness in the footwell before replacing the pedal assembly.

What it means

P2122 reports that pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking.

Drive-by-wire pedals carry two redundant position sensors precisely so a single lying sensor can never command acceleration. When either circuit misbehaves, the computer responds with reduced power — annoying by design, because the failure mode being prevented is unintended throttle.

The steps below run cheapest-first — because in this family, the cheap causes really are the common ones.

P2122 symptoms: what you'll notice

Reduced power or “limp mode” — the car barely responds to the gas pedal, usually with a wrench or reduced-power warning on the dash.
The engine stays near idle no matter how hard you press the pedal.
It may start and idle perfectly, then refuse to accelerate.
Sometimes intermittent: normal one drive, crippled the next, as a loose connection makes and breaks contact.

Common causes

Ordered from most to least likely.

1.

See the diagnosis steps

This family shares its suspect list; the steps walk it in cost order.
2.

Wiring or connector damage

The universal suspect for circuit-flavored codes.
3.

The component named by the code

Condemned by measurement, never by guess.

How to fix it: diagnosis, step by step

Cheapest and most likely checks first.

1 Respect the limp mode

Reduced power with these codes is the system working. Drive gently or not at all until diagnosed — highway merges in limp mode are their own hazard.
2 Inspect the footwell

The pedal's connector and harness live where drinks spill, boots kick, and rodents visit. Unplug, inspect pins, reseat — a high percentage of pedal codes end here.
3 Watch both signals

On a scanner showing both pedal channels, sweep slowly: two smooth traces in their designed relationship = circuits fine (recheck connector); a dropout in one channel = that sensor, which means the sealed pedal assembly.

Parts & tools you may need

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Related codes

Frequently asked questions

What does code P2122 mean?: P2122 means pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking. It’s serious — diagnose it promptly to avoid expensive damage.
What does P2122 mean in plain words?: Pedal sensor D's signal is stuck low — the computer can't trust what your foot is asking. Expect reduced-power mode; inspect the pedal connector and harness in the footwell before replacing the pedal assembly.
Can I just clear it and drive?: It returns — pedal plausibility is checked continuously. Clearing is for confirming a repair, not living with one missing.
Pedal assembly or throttle body — which am I buying?: P2122–P2128 = pedal-side sensors (the pedal assembly). P0120-family and P2135 = throttle-body-side. The code prefix decides which end of the wire you're shopping for.