P0221🔧 Engine management / throttle and accelerator pedal sensorsStop and fix promptly

P0221: Throttle/Pedal Position Sensor B Range/Performance (Meaning, Causes, Fixes)

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0221 means

The throttle position sensor on the throttle body, and on many newer cars the pedal position sensor on the accelerator pedal, tell the engine computer how far you're pressing the gas. 'B' refers to a particular sensor or circuit, and which one it is depends on your vehicle. P0221 is the 'range/performance' code for that B circuit: rather than a plain open or short, the signal is outside what the computer expects. OBD-Codes.com says it sets when the computer sees a throttle angle greater or less than it should be for a given engine RPM. RepairPal describes it more broadly, saying the code sets when the computer detects a problem with the sensor or its circuit. Its siblings are P0220 (general B circuit fault), P0222 (B circuit low) and P0223 (B circuit high). The sources also disagree on how the signal behaves: OBD-Codes.com says the reading goes up as the throttle opens, about 0.5 volts at idle to about 4.5 volts at full throttle, while RepairPal says the sensor sends a decreasing voltage as it rotates toward full acceleration and then mentions a 'decreasing or increasing' signal. Which is true depends on your car, so use your service manual's values. They also word the code differently: OBD-Codes.com calls it 'Throttle Position Sensor/Switch B Circuit Range/Performance', while RepairPal uses 'Throttle/Pedal Position Sensor/Switch B Circuit' and covers both the throttle and the pedal sensor. It is a generic code that can appear on any OBD-II vehicle.

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed promptly. RepairPal rates P0221 Urgent and says the engine computer may limit the car to about 20 mph or less (limp home mode) because it can't accurately tell how much power you're asking for. OBD-Codes.com gives no severity rating but lists stumbling on acceleration or deceleration, black smoke and even a no-start among the symptoms. Avoid highway or heavy-traffic driving until it's checked, since the car may not respond normally to the gas pedal.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Faulty throttle or pedal position sensor, including an intermittent internal open or short (both sources)
  2. Harness rubbing through and causing an open or short, or chafed wiring (both sources)
  3. Bad or corroded connection at the sensor (both sources)
  4. Water or corrosion in the connector or sensor (OBD-Codes.com)
  5. Dirty or carbon-filled throttle bore (RepairPal)
  6. Torn or jammed floor mat interfering with the pedal (RepairPal)
  7. Faulty engine computer (PCM), less likely (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check that the floor mat isn't bunched up, torn or pushing on the accelerator pedal. RepairPal lists this as a cause and says pedal sensors are sometimes replaced when the mat was the real problem.
  2. Inspect the sensor connector and harness for rubbing, loose pins, corrosion or water. OBD-Codes.com says to replace the sensor if water has got into the connector.
  3. Look for heavy carbon in the throttle body and clean it following your manufacturer's procedure. RepairPal says sensors are often replaced when a dirty throttle body was the real problem.
  4. With a scan tool, compare the sensor reading at idle and wide open throttle with your service manual's specs. OBD-Codes.com gives about 0.5 volts at idle and 4.5 volts at full throttle as a general guide, but RepairPal notes some sensors move the other way.
  5. OBD-Codes.com says a scan tool can miss a brief signal dropout, so an oscilloscope and a wiggle test on the connector and harness are the way to catch an intermittent fault. It also says the signal wire should never show battery voltage (12 volts).

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The car is in limp mode, won't start or stumbles badly
  • You need an oscilloscope to catch an intermittent signal dropout
  • The 5-volt reference or ground at the sensor is missing, or the signal wire shows battery voltage
  • The code returns after you've cleaned the throttle body, fixed the wiring or replaced the sensor

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0221?

It's not a good idea. RepairPal rates it Urgent and says the car may be limited to about 20 mph in limp home mode, and OBD-Codes.com lists stumbling, black smoke and a no-start among the symptoms.

What's the difference between P0220, P0221, P0222 and P0223?

All four are 'B' throttle or pedal position sensor codes. P0220 is the general circuit fault, P0221 means the signal is out of its expected range or doesn't make sense, P0222 means the voltage is too low and P0223 means it's too high.

Can a floor mat really cause P0221?

RepairPal lists a torn or jammed floor mat as a common cause and says pedal sensors are sometimes replaced when the mat was the real problem, so it's worth checking first.

Why can't my scan tool see the problem?

OBD-Codes.com says scan tools sample many readings over one or two data lines and can miss a brief dropout, so an oscilloscope is needed to catch an intermittent open or short in the sensor signal.

How much does it cost to fix P0221?

Neither source gives a repair cost for P0221. It can range from moving a floor mat or cleaning the throttle body to wiring repair or a new sensor, so get it diagnosed first.

Sources

  1. OBD-Codes.com: P0221 Throttle Position Sensor/Switch B Circuit Range/Performance Problem
  2. RepairPal: P0221 Throttle/Pedal Position Sensor/Switch B Circuit (rated Urgent)

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.