P0228: Throttle/Pedal Position Sensor/Switch C Circuit High Input

What P0228 tells you, and what it does not

This code sets when the pedal's sensor C signal voltage reads above the maximum value the computer expects across the pedal's full travel, usually pointing to an open circuit or a short to the sensor's reference voltage. The computer falls back to the pedal's other sensor to keep the car drivable in a limited way.

The code sits in the accelerator pedal 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
• Pedal response that feels flat or capped
• Check engine light
• No response to sudden pedal input
• Idle that hunts slightly

What causes P0228?

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 accelerator pedal position sensing fault becoming an expensive guess.

Open circuit or broken wire in the sensor C signal path is the one to rule out before anything else. A broken wire is the most direct cause of a signal stuck high.

Working out which cause it is

Start with freeze frame. Pedal position at the fault shows whether the high reading appeared at rest 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 C voltage at rest and through the pedal's travel confirms whether the signal is pinned high or missing entirely.

The order worth working in

• 1. Open circuit or broken wire in the sensor C signal path: A broken wire is the most direct cause of a signal stuck high.
• 2. Wire shorted to the reference voltage supply: A chafed wire touching the reference wire pushes the signal to the supply voltage.
• 3. Failed sensor C element with an open circuit: The sensor element itself can open internally with age.
• 4. Corroded ground connection at the pedal assembly: A poor ground can push the pedal's sensor readings high.
• 5. Chafed wiring near the pedal bracket: Repeated pedal movement flexes nearby wiring until it wears through.

What P0228 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 pedal 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 P0228?

Running on a single pedal 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.