P0227 Throttle/Pedal Position Sensor/Switch C Circuit Low Input

P0227 indicates throttle or pedal position sensor C circuit low. The C signal is below expected voltage or pulled toward ground.

Code details

Generic OBD-II · P0

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the throttle body before isolating whether the low C signal is wiring, sensor, or reference related.

Symptoms of P0227

Check-engine light on, sometimes with rough or uneven running.
Hesitation, surging, or a noticeable change in fuel economy.
Occasionally hard starting or a smell of unburnt fuel.

Common causes of P0227

A failing or contaminated sensor (MAF, MAP, oxygen or air-fuel sensor).
Intake or vacuum leaks, or an exhaust leak near an upstream sensor.
Wiring, connector, or fuel-delivery problems that skew the reading.

Useful checks before replacing parts

Measure sensor C signal voltage, reference, ground, and continuity while checking for short-to-ground conditions.
Compare sensor C with other throttle or pedal tracks and commanded throttle position during a controlled sweep.
Inspect connector terminals, harness rub points, water intrusion, shared reference faults, and freeze-frame throttle data.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.