P0221 Throttle or pedal position sensor B signal outside its normal range

Throttle/pedal position sensor/switch B circuit range/performance

P0221 in short

P0221 means the computer sees the second throttle or pedal position sensor reading outside its expected range or disagreeing with the first. Typical causes are a worn pedal or throttle sensor or a wiring fault. Expect reduced engine power, so avoid heavy traffic and get it checked soon.

Drive-by-wire cars use two position signals so the computer can cross-check them. P0221 is set when the second sensor, B, reads out of range or does not match sensor A.

When the signals disagree, the computer cannot tell how far the pedal or throttle is open. Kelley Blue Book says it limits the throttle to a few degrees of opening as a failsafe. GM, Saturn and Volkswagen bulletins describe a reduced-power message or EPC light with this code.

The cause may be the sensor, the circuit or a throttle body that has failed, so it is worth reading related codes before replacing anything.

Most likely causes

  1. Faulty pedal or throttle position sensor B

    Common general cause
    Why it ranks here
    Reference pages for P0221 name the sensor first, and Ford bulletin 03B03 prescribes replacing an adjustable pedal sensor when this code sets.
    What would change this
    Rises if the two sensor readings disagree as you press the pedal slowly. Falls if both track together.
    How to test the accelerator pedal position sensor

  2. Wiring, connector or reference-voltage fault

    Common general cause
    Why it ranks here
    A shared 5-volt supply or ground problem or a damaged connector gives an out-of-range reading on one channel.
    What would change this
    Rises if other throttle or pedal codes are stored with it. Falls if wiring tests clean.

  3. Throttle body fault, or a model-specific software or part issue

    Supported by vehicle data
    Why it ranks here
    GM, Saturn, Cadillac, Buick, Volkswagen and Audi published bulletins listing this code with reduced power or EPC lights, but the NHTSA summaries do not all state the repair.
    What would change this
    Rises if your vehicle is one of those models and a dealer finds an applicable update. Falls on other vehicles.
    How to test the electronic throttle body

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes. Note P0121, P0122, P0222, P2135 or P2138 stored with P0221.

    Low riskTool: OBD-II scan tool

    • IfSeveral throttle or pedal codes are stored

      It meansA shared circuit or the throttle assembly is more likely.

      Go to step 2

    • IfP0221 is the only code

      It meansCompare the two sensor readings next.

      Go to step 2

  2. Watch both throttle or pedal sensor values on a scan tool while pressing the pedal slowly.

    Low riskTool: scan tool with live data

  3. Ask a dealer whether your VIN has a bulletin or software update for this code.

    Low risk

Symptoms

  • Reduced engine power message, wrench light or EPC light
  • Weak, limited acceleration
  • Check engine light
  • Engine stalls or power drops away in traffic Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power

How to fix

  1. With the engine off, check the pedal and throttle connectors for loose or corroded pins and reseat them.

  2. Ask a dealer about open bulletins or software updates for your VIN.

Parts and cost context

  • Accelerator pedal position sensor:Often part of the pedal assembly; confirm the fault with live data first.
  • Electronic throttle body:Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Ford

  • 2002–2003 · Excursion

    Supported by vehicle data

    Ford bulletin 03B03 replaces the adjustable accelerator pedal sensor on 2002 to 2003 Excursion and Super Duty with the light on. Not verified as current.

  • 03B03Status unverified

    Adjustable accelerator pedal sensor replacement with MIL on

    2002–2003excursion, f-250, f-350 · issued · NHTSA 10001076

    Replace the adjustable accelerator pedal sensor on vehicles with an adjustable pedal problem and the light on with accelerator pedal codes.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Saturn

  • 2000–2003 · Vue

    Supported by vehicle data

    Saturn bulletin 030604043 covers a check engine light and possible reduced power lamp with P0221 and related codes. Not verified as current.

  • 030604043Status unverified

    Service engine soon light and reduced power lamp with P0121, P0221, P2135

    2000–2003vue · issued · NHTSA 10003592

    Covers a check engine light and possible reduced power lamp with P0121, P0221 and/or P2135 on Saturn models.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Buick

  • 2004–2005 · Rendezvous

    Supported by vehicle data

    GM bulletin 050604032 covers reduced engine power with P0221 and other throttle codes on the Rendezvous. Not verified as current.

  • 050604032Status unverified

    Reduced engine power with P0121, P0221, P2119, P2122, P2138, P2176

    2004–2005rendezvous · issued · NHTSA 10017358

    Covers reduced engine power and a check engine light with one or more of these throttle and pedal codes set.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Cadillac

  • 2004 · SRX

    Supported by vehicle data

    GM bulletin 01879 covers reduced power with P0221 on the 2004 SRX and CTS. Not verified as current.

  • 01879Status unverified

    Reduced engine power complaint setting throttle codes

    2004srx, cts · issued · NHTSA 10006478

    Covers a reduced engine power complaint with P0121, P0221, P2119, P2122, P2138 and P2176.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Volkswagen

  • 2007 · Passat

    Supported by vehicle data

    Volkswagen bulletin 010767 covers the EPC light and throttle codes P0121/P0221 on the 2007 Passat. Not verified as current.

  • 010767Status unverified

    EPC light and throttle body codes P0121/P0221

    2007passat · issued · NHTSA 10023941

    Covers the EPC warning light on and/or throttle body codes P0121 and P0221 stored in the engine computer.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P0121The throttle position sensor A signal doesn't agree with what the engine computer expects, even though the voltage is within range

    Same system Supported by vehicle data

    GM, Saturn and Volkswagen bulletins list P0121 and P0221 together for the same throttle/pedal concern.

  • P0222The second throttle (or pedal) position sensor signal is reading lower than its circuit should ever allow, so the computer treats it as an open or shorted circuit

    Same system Common general cause

    P0222 is the low-input form of the same B circuit.

  • P2138Two accelerator pedal position sensor signals (D and E) that should agree with each other don't

    Same system Supported by vehicle data

    GM bulletins list P2138 with P0221 for pedal sensor correlation.

All Electronic throttle and accelerator pedal codes

P0221 questions

Why is my car in limp mode with P0221?

The computer cannot trust the throttle or pedal signal, so it limits engine power as a protection. Fix the cause and clear the code.

Does P0221 mean the throttle body is bad?

Not necessarily. The pedal sensor, wiring or connector can set it. Compare both sensor readings first.

Sources and review

  1. P0221 OBD-II code — Kelley Blue Book
  2. Saturn 030604043: Service engine soon light and reduced power lamp with P0121, P0221, P2135 — NHTSA manufacturer communications ,
  3. Cadillac 01879: Reduced engine power complaint setting throttle codes — NHTSA manufacturer communications ,
  4. P0221 trouble code explanation — TroubleCodes.net
  5. P0221 OBD-II trouble code — PartsAvatar
  6. Ford 03B03: Adjustable accelerator pedal sensor replacement with MIL on — NHTSA manufacturer communications ,
  7. Buick 050604032: Reduced engine power with P0121, P0221, P2119, P2122, P2138, P2176 — NHTSA manufacturer communications ,
  8. Volkswagen 010767: EPC light and throttle body codes P0121/P0221 — NHTSA manufacturer communications ,
Last reviewed
Written by
Saurabh K.
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