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DTC codes / P02xx · Fuel and air metering (injector circuits) / P0225

P0225Throttle/Pedal Position Sensor/Switch 'C' Circuit

P0225 indicates that the engine control module has detected an abnormal signal on the 'C' circuit of the throttle or pedal position sensor, which is often the second independent track inside the accelerator pedal assembly. The computer compares this signal against the other throttle position sensor circuits and sets the code when the voltages do not agree or fall outside the expected range.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering (injector circuits)

Symptoms you may notice

  • The check engine light or electronic throttle control warning lamp illuminates steadily.
  • The engine may enter limp mode with severely reduced power and a maximum speed limit.
  • The accelerator pedal may feel unresponsive or require excessive travel to accelerate.
  • Rough or erratic idle quality may occur as the computer struggles to determine the correct throttle angle.
  • Often no symptoms besides the warning light, especially if the redundant sensor circuit still provides a usable signal.

Common causes, most likely first

  1. A worn or dirty accelerator pedal position sensor track inside the pedal assembly.
  2. An open or shorted wire in the sensor 'C' circuit, often at a flex point near the pedal or under the dash.
  3. Corroded or loose terminals at the pedal sensor connector or the engine control module connector.
  4. A faulty electronic throttle body whose internal position sensors do not correlate with the pedal signal.
  5. Water intrusion into the pedal sensor connector or throttle body connector causing signal corruption.
  6. A failing engine control module, which is rare but possible after all other circuits are verified.

How to diagnose and fix it

  1. Read all stored and pending codes with a scan tool and record the freeze-frame data for P0225.
  2. Inspect the accelerator pedal sensor connector and wiring for corrosion, chafing, or loose pins, and repair as needed.
  3. Back-probe the sensor 'C' signal wire and compare its voltage sweep against the other pedal sensor circuits while slowly pressing the pedal.
  4. Check the throttle body connector and wiring for similar faults, and verify that the throttle plate moves freely without carbon binding.
  5. Perform a manufacturer-specific throttle relearn or pedal calibration procedure after any repair or replacement.
  6. Replace the accelerator pedal assembly if the internal sensor track is proven faulty through voltage testing.
  7. Clear the codes and road test the vehicle through several complete drive cycles to confirm the repair.

Why P0225 often is not the pedal

  • A dirty throttle body that causes the plate to bind can set P0225 because the computer sees the pedal signal and throttle position signal disagree during a commanded movement.
  • Many technicians replace the accelerator pedal assembly only to find a chafed wire in the harness near the pedal bracket, so always perform a loaded voltage drop test on the signal circuit.
  • P0225 can be set by a weak battery or charging system fault that causes a momentary voltage spike or drop during cranking, corrupting the sensor reference voltage.
  • On some vehicles, the 'C' circuit is actually the second track inside the pedal sensor, and a failure there may not cause any drivability symptom until the primary track also fails.
  • After replacing the pedal or throttle body, failing to perform the relearn procedure will often cause P0225 to return immediately even though the hardware is good.

Can I keep driving with P0225?

The vehicle is usually safe to drive to a repair shop, but expect reduced engine power and avoid highways or situations that require sudden acceleration. If the engine enters limp mode with very limited speed, drive only a short distance at low speed and arrange a tow if the pedal response becomes unpredictable.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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