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

What P0221 means

P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 2, places it in the fuel and air metering, injector circuits subsystem; the last two digits identify the specific fault.

In the standard's wording this code family covers throttle position sensors and, on electronic throttle ("drive-by-wire") vehicles, accelerator pedal position sensors. Electronic throttle systems use at least two signals for each so the module can cross-check them; "A", "B" and "C" identify which signal is at fault, and the assignment is set by the manufacturer.

What “Range/Performance” means here

"Range/Performance" means the circuit is electrically intact — the signal sits inside its normal window — but the value does not make sense for the operating conditions. The module cross-checks it against what other inputs predict (a rationality test). That usually points at the throttle / pedal position sensor itself or the system it measures, rather than at the wiring.

What you may notice

Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0221:

• Reduced power or a limp-home mode with limited throttle
• Hesitation or surging
• Erratic or high idle
• Harsh or delayed gear changes on automatic transmissions

Where to start diagnosing P0221

1. Identify from the vehicle's service information whether the "A/B/C" signal is on the throttle body or the pedal assembly.
2. Inspect the connector and harness at that component; flex the wiring while watching live data.
3. Sweep the throttle or pedal slowly and watch for dropouts or jumps in the position signal.
4. On electronic throttles, check the throttle body for carbon build-up that can cause position disagreement.

Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.

Live data to watch

These standard OBD2 values relate to P0221. Support varies by vehicle; a value your car does not report will simply be missing.

Related codes

Codes from the same throttle / pedal position sensor family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.

Further reading

• It hesitates when you ask for power
• It stalls when you come to a stop

Frequently Asked Questions