Faulty throttle position sensor B, either the sensor element itself or the second track inside the electronic throttle body; Damaged, chafed, or corroded wiring in the sensor B circuit, including the signal, ground, or reference voltage wires; Loose or contaminated electrical connector at the throttle position sensor or throttle body; Failed or sticking electronic throttle body assembly affecting sensor B output; Poor electrical ground for the throttle position sensor circuit; Rarely, a fault in the powertrain control module itself

DTC codes / P02xx · Fuel and air metering (injector circuits) / P0220

P0220Throttle Position Sensor B Circuit Malfunction

Q: What does code P0220 mean?

Throttle Position Sensor B Circuit Malfunction. P0220 indicates that the powertrain control module has detected an abnormal signal on the throttle position sensor B circuit, which is often the second track of a redundant throttle position sensor or a sub-sensor within the electronic throttle body. The computer compares this signal against the primary throttle position sensor and other correlated inputs, and it sets the code when the B circuit voltage falls outside the expected range or does not agree with the primary sensor.

P0220 indicates that the powertrain control module has detected an abnormal signal on the throttle position sensor B circuit, which is often the second track of a redundant throttle position sensor or a sub-sensor within the electronic throttle body. The computer compares this signal against the primary throttle position sensor and other correlated inputs, and it sets the code when the B circuit voltage falls outside the expected range or does not agree with the primary sensor.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or a limp-home mode with limited throttle response
Hesitation, stumble, or surging during acceleration
Unstable or fluctuating idle speed
Poor fuel economy or increased emissions
In some vehicles, the engine may stall or refuse to rev beyond a limited RPM

Common causes, most likely first

Faulty throttle position sensor B, either the sensor element itself or the second track inside the electronic throttle body
Damaged, chafed, or corroded wiring in the sensor B circuit, including the signal, ground, or reference voltage wires
Loose or contaminated electrical connector at the throttle position sensor or throttle body
Failed or sticking electronic throttle body assembly affecting sensor B output
Poor electrical ground for the throttle position sensor circuit
Rarely, a fault in the powertrain control module itself

How to diagnose and fix it

Perform a visual inspection of the throttle body, sensor connector, and wiring for damage, corrosion, or looseness
Use a scan tool to read live data for throttle position sensor B and compare it to sensor A while slowly opening the throttle
Check reference voltage and ground at the sensor B connector with a multimeter, looking for approximately 5 volts and a good ground
Back-probe the sensor B signal wire and verify the voltage changes smoothly through the throttle range without dropouts or spikes
If wiring and connectors are good, test the sensor B resistance or voltage output according to the manufacturer's specification
Replace the throttle position sensor or electronic throttle body if testing confirms an internal fault
Clear the codes and perform a throttle body relearn or idle relearn procedure as required by the vehicle manufacturer

Before you replace the throttle body

A common misdiagnosis is replacing the entire electronic throttle body when the real problem is a chafed wire near the connector or a corroded ground that only acts up when the engine moves under load.
P0220 can be set by a weak or failing battery or charging system, because low voltage can cause the throttle position sensor B signal to fall out of range during cranking or heavy electrical load.
On many vehicles, the throttle position sensor B circuit is the second track of a redundant sensor, so a failure may not produce any drivability symptoms until the primary sensor also degrades, making the code easy to ignore.
After any repair involving the throttle body or sensor, a relearn procedure is often required; skipping it can cause a repeat code or poor idle quality even though the hardware is fixed.
A sticking or carbon-fouled throttle plate can cause the sensor B voltage to change erratically at closed throttle, mimicking a sensor failure and leading to unnecessary parts replacement.

Can I keep driving with P0220?

You can usually drive the vehicle to a repair shop, but expect reduced engine power or limp-home mode and avoid heavy acceleration or highway merging until the fault is repaired. If the engine stalls, idles erratically, or refuses to rev, stop driving and have the vehicle towed to prevent a dangerous loss of power.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.