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

What does P0221 mean?

Channel B produces a signal, but it is implausible or does not track the expected position. A worn sensing track can remain inside the allowed voltage range while still giving the computer a misleading position.

Generic OBD-II definition: Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance. Confirm applicability in your vehicle service information.

Common causes

• Worn or failing B sensor
• Harness rubbing or poor connector contact
• Incorrect sensor adjustment where applicable

Symptoms

• Erratic acceleration
• Poor idle
• Reduced-power mode

Diagnostic focus

A range/performance code is not automatically a low-voltage code. Look for flat spots, sudden changes, or disagreement with the other position channel rather than a single fixed cutoff.

Can I keep driving with P0221?

Severity: High Unreliable throttle response can be dangerous. Do not continue driving with surging, stalling, or reduced acceleration that makes traffic unsafe; arrange recovery instead. Do not force an electronic throttle plate.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Graph the B signal smoothly through its range
• Inspect the connector for moisture and loose terminals
• Check the specified A/B relationship and adjustment procedure

Sources & review

• OBD-Codes.com: P0221
• TroubleCodes.net: generic code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.