How much does it cost to fix P0221?

DIY repair typically costs $10–$150 for parts. Professional repair runs $100–$500 including parts and labor.

P0221

Powertrain

Moderate

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

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Code P0221 means the powertrain control module (PCM) has determined that the Throttle/Pedal Position Sensor B circuit output is not performing within its expected range. Unlike P0222 (too low) or P0223 (too high), this code indicates the signal is technically within range but doesn't track properly — it may be erratic, have dead spots, or not match the expected relationship to sensor A's readings.

This code is particularly interesting because it can sometimes be caused by something as simple as a dirty throttle body. Carbon buildup on the throttle plate and bore can cause the plate to stick slightly or move unevenly, making the TPS B signal appear erratic. Before replacing any parts, try cleaning the throttle body with throttle body cleaner and a soft cloth. This $5–$10 fix resolves the issue in a surprising number of cases.

If cleaning doesn't resolve the code, the TPS sensor itself may be worn internally. As these sensors age, their internal resistance track can develop dead spots or areas of uneven wear, causing the voltage output to jump or not track smoothly. In this case, the sensor (or entire throttle body on vehicles with integrated sensors) will need to be replaced. After any TPS-related repair, a throttle relearn procedure is typically required to recalibrate the PCM's understanding of the throttle's idle and full-open positions.

Severity

Moderate — Address SoonThis Week

Symptoms

•Check Engine light is on
•Vehicle goes into limp mode or reduced power mode
•Inconsistent or jerky throttle response
•Engine surges or hesitates during acceleration
•Unstable idle speed
•Vehicle may limit top speed

Likely Causes

Worn or failing throttle position sensor B40%

The TPS B sensor is producing readings that are within the valid voltage range but don't track smoothly or don't correspond correctly to the actual throttle position — a sign of internal wear.

Carbon buildup on throttle body25%

Excessive carbon deposits on the throttle plate and bore can interfere with smooth throttle movement and cause the TPS B reading to be erratic or out of expected range.

Intermittent wiring or connector issue20%

A loose pin, corroded terminal, or chafed wire in the TPS B circuit creates intermittent signal dropouts that appear as range or performance issues.

Faulty throttle body or pedal position sensor15%

Either the electronic throttle body or the accelerator pedal position sensor assembly has worn internal components affecting the B circuit readings.