What it means
A general electrical fault was detected in the secondary (B) throttle or pedal position sensor circuit. Modern drive-by-wire systems use redundant TPS tracks; the ECU compares them and flags this code on the B channel when out of range.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The throttle or accelerator-pedal position sensor B circuit sends the PCM a signal representing the position of the throttle or pedal. P0220 indicates a general electrical fault in that B circuit, rather than a specific low or high signal; the PCM may limit throttle response as a safeguard.
Common causes
Most likely first.
- TPS B element failed
- Wiring or connector fault
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
How to diagnose it
- Record freeze-frame data and check for other throttle or pedal position codes to identify whether the fault appeared while pressing the pedal or moving the throttle.
- Use live data to observe sensor B while slowly moving the accelerator pedal or throttle, and compare it with available related position readings.
- Inspect the B sensor connector and harness at the pedal or throttle body for loose pins, corrosion, abrasion, or damage.
- Check the B circuit’s reference, ground, and signal wiring against the vehicle wiring diagram and manufacturer’s specification.
- Test the sensor or switch B and its circuit under the manufacturer’s diagnostic procedure to distinguish a sensor fault from a wiring or module issue.
Common fixes
- Reconnect or clean a loose or corroded sensor B connector.
- Repair damaged wiring or poor connections in the B circuit.
- Replace the throttle or pedal position sensor B if circuit tests confirm it has failed.
- Repair a control-module fault only if the circuit and sensor test correctly and the prescribed diagnosis confirms it.
Can I keep driving?
Because throttle response may be limited or unpredictable, avoid driving in fast traffic or situations that require quick acceleration; stop if control feels unsafe. Continued operation with a faulty position signal can cause hesitation or stalling.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.