Faulty throttle position sensor B or accelerator pedal position sensor B (worn track or internal failure); Damaged, chafed or corroded wiring or connector in the sensor B signal, reference voltage or earth circuit; Dirty or carbon-fouled throttle body causing the throttle plate to stick and the two sensor signals to disagree; Faulty throttle body or electronic throttle motor assembly with integral sensors; Low or unstable sensor supply voltage or poor earth, for example from a weak battery or charging fault; Fault inside the engine control unit.

P0220

Throttle/Pedal Position Sensor/Switch B Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
2: AreaFuel and air metering (injector circuit)
20: FaultThe specific fault in that area

What it means

P0220 is the generic code for a fault in the Throttle/Pedal Position Sensor/Switch 'B' circuit. The engine control unit has seen a signal from sensor B that is out of range, erratic or missing, or that does not agree with the signal from the other sensor (usually sensor A). Which physical sensor is 'B' depends on the make, model and engine, so check the manufacturer wiring information.

Symptoms

Engine warning light on
Car goes into limp mode with reduced power
Poor or delayed throttle response
Unstable or high idle, or stalling
Hesitation or surging when accelerating
Cruise control not working

Possible causes

Faulty throttle position sensor B or accelerator pedal position sensor B (worn track or internal failure)likely
Damaged, chafed or corroded wiring or connector in the sensor B signal, reference voltage or earth circuitlikely
Dirty or carbon-fouled throttle body causing the throttle plate to stick and the two sensor signals to disagreepossible
Faulty throttle body or electronic throttle motor assembly with integral sensorspossible
Low or unstable sensor supply voltage or poor earth, for example from a weak battery or charging faultpossible
Fault inside the engine control unitrare

How to diagnose

Read all stored and pending codes and the freeze frame data, and note any other throttle, pedal or reference voltage codes.
Check the manufacturer information to confirm which sensor is 'B' on this model, whether it is in the throttle body or the pedal assembly.
Visually inspect the sensor wiring and connectors for chafing, water ingress, corrosion, bent pins or loose terminals.
Check battery condition and charging voltage, as low voltage can upset sensor readings.
With a scan tool, watch the live data for sensors A and B while slowly moving the pedal or throttle through its full range, looking for dropouts, jumps or mismatched readings.
Inspect the throttle body for heavy carbon build-up or a sticking plate, and check the plate moves smoothly.
Test the sensor reference voltage, signal and earth circuits with a multimeter against the manufacturer specification, including checks for shorts and open circuits.
If wiring and supply are good, compare against known-good values and check for a relevant software update or fault history before condemning the sensor or control unit.

How to fix

Repair or replace damaged wiring and renew corroded or damaged connectors.
Replace the faulty accelerator pedal assembly or throttle body, depending on where sensor B is fitted.
Clean the throttle body with a suitable cleaner following the manufacturer procedure, then carry out any throttle adaptation or relearn required.
Correct battery, charging or earth faults that affect the sensor supply.
Replace or reprogram the engine control unit only after all other causes are ruled out, and only if the manufacturer confirms it.

Can I keep driving?

Medium severity

The car may drive in limp mode with reduced power and unpredictable throttle response, which can be unsafe in traffic. Get it checked soon and avoid long journeys or overtaking until it is fixed.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.