P0222: Throttle/Pedal Position Sensor/Switch B Circuit Low Input

What P0222 tells you, and what it does not

This code sets when sensor B's signal voltage drops below the minimum value the computer expects across the full range of throttle travel, indicating a short to ground or an open circuit rather than a calibration drift. It is a hard electrical fault, so the computer usually falls back to a limp mode relying on sensor A alone.

The code sits in the throttle position sensing area and is reported by the comprehensive component monitor. It names the circuit or the condition where the computer saw a reading outside its expected range. It does not name a failed part, and several genuinely different faults set this same code, which is the whole reason the causes below are ordered rather than listed.

What people usually notice

• Reduced power mode
• Throttle response that feels flat or capped
• Check engine light
• Idle that hunts slightly
• No response to sudden throttle input

What causes P0222?

The causes below are ordered by how often they turn out to be the answer, cheapest and most common first. That order matters more than the list itself: the expensive component named in the code text is very rarely the first thing to replace, and working down from the top is what stops a throttle position sensing fault becoming an expensive guess.

Wire shorted to ground in the throttle body harness is the one to rule out before anything else. This is the most direct cause of a signal stuck low.

Working out which cause it is

Start with freeze frame. Throttle position at the fault shows whether the low reading appeared at idle or partway through the pedal's travel. That snapshot is taken at the instant the code set, and it is the single most useful piece of evidence you have, which is also why clearing the code before reading it is such a costly habit.

This code is diagnosed by watching values change rather than by reading the number again, so the tool has to stream live data and hold freeze frame. Checking live sensor B voltage at rest and through the pedal's travel confirms whether the signal is stuck low or missing entirely.

The order worth working in

• 1. Wire shorted to ground in the throttle body harness: This is the most direct cause of a signal stuck low.
• 2. Corroded or bent connector pin at the throttle body: Moisture at this connector location bridges pins over time.
• 3. Failed sensor B element with an internal short: The sensor's internal element can short as it ages.
• 4. Blown reference voltage supply shared with other sensors: A shared 5 volt supply failing affects more than just this one circuit.
• 5. Failed accelerator pedal sensor module: On drive-by-wire pedals the sensor pair lives inside the pedal assembly itself.

What P0222 means for driving the car

Drivable in limp mode for a short trip, but arrange a repair soon since the car is running on a single throttle sensor.

This is a severity 2 of 4 code. It will not usually strand you, but it will fail an emissions test while it is present, and the underlying fault rarely gets cheaper by being left alone.

What does it cost to ignore P0222?

Running on a single throttle sensor removes a layer of safety redundancy, and the reduced power mode it triggers costs real drivability until repaired.

There is also the diagnostic cost of waiting. Freeze frame data, pending code history and the readiness monitor state all describe the fault as it was when it set, and all of it is lost the moment somebody clears the code to make the lamp go out.