P0221 — Throttle/Pedal Position Sensor/Switch B Circuit Malfunction
Drive with caution — fix soon.
What P0221 means
This code means the engine computer detected a problem in the 'B' circuit of the throttle or accelerator pedal position sensor, which reports how far the throttle or pedal is pressed. A fault is usually caused by a bad sensor, damaged wiring, or poor connections, and it can put the car into a reduced-power safety mode. Repairs typically involve testing the sensor circuit and replacing the sensor or repairing the wiring.
Common symptoms
- Check engine light is on
- Reduced engine power or limp mode
- Hesitation or surging when pressing the gas
- Unstable or rough idle
- Poor or inconsistent throttle response
Common causes
- Faulty throttle or accelerator pedal position sensor
- Damaged wiring or corroded connectors at the sensor
- Open or short circuit in the sensor's B circuit
- Dirty or worn throttle body
- Engine control module (ECM) fault
Typical repair cost
$120 – $500
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0221 code?
Often yes, but the car may enter reduced-power mode and respond poorly to the gas pedal. That can be unsafe in traffic, so get it checked soon.
How much does it cost to fix a P0221 code?
Repairs usually cost between $120 and $500, depending on whether it's a wiring fix or a sensor or throttle body replacement. Diagnosis confirms the exact cause.
Is a P0221 code serious?
It's moderate. The car usually still runs, but reduced power and poor throttle response can affect safety, so it shouldn't be left unaddressed.
Why does my car lose power with a P0221 code?
When the throttle position signal is unreliable, the computer often limits power to stay safe. Fixing the sensor or wiring restores normal throttle response.