P0221 Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance

P0221 indicates a range or performance issue in throttle or pedal position sensor/switch B. The redundant channel does not match expected values or sensor A behavior.

Code details

Generic OBD-II · P0

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the throttle body before comparing redundant channels; the mismatch pattern matters.

Symptoms of P0221

Check-engine light on, sometimes with rough or uneven running.
Hesitation, surging, or a noticeable change in fuel economy.
Occasionally hard starting or a smell of unburnt fuel.

Common causes of P0221

A failing or contaminated sensor (MAF, MAP, oxygen or air-fuel sensor).
Intake or vacuum leaks, or an exhaust leak near an upstream sensor.
Wiring, connector, or fuel-delivery problems that skew the reading.

Useful checks before replacing parts

Compare throttle/pedal sensor B with sensor A and commanded throttle angle through the full travel range.
Check connector condition, reference voltage, sensor ground, signal wiring, and throttle or pedal assembly movement.
Inspect for dead spots, noisy signal, adaptation issues, or related electronic throttle control codes.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.