P0227

Universal

Throttle/Pedal Position Sensor/Switch C Circuit Low Input

Definition source: General OBD-II reference catalog

Definition verification: Not independently verified for display.

Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium

High Severity

The engine computer has detected a low input in the C circuit associated with a throttle or pedal position sensor/switch. These sensors report throttle or accelerator-pedal position so the computer can manage engine response. A low signal may cause reduced power, poor response, or protective operation, but the code alone does not prove that a sensor needs replacement.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the vehicle has weak, erratic, or unpredictable acceleration, reduced power that makes traffic unsafe, or stalls, stop driving when it is safe to do so and arrange an inspection. Avoid relying on the vehicle for a trip where a sudden loss of power could create danger.

Common Symptoms

The check-engine light may be on, while the vehicle otherwise seems to drive normally.
Slow, weak, or inconsistent acceleration may occur if the computer receives an unreliable position signal.
The engine may enter a reduced-power or protective mode to limit throttle response.
The engine may hesitate, run unevenly, or stall if the fault disrupts engine control.
There may be no noticeable symptoms if the computer can compensate or the fault is intermittent.

Common Causes

A damaged, contaminated, or poorly connected connector can interfere with the sensor circuit.
Chafed, broken, corroded, or shorted wiring can pull the circuit signal low.
A throttle or pedal position sensor/switch may produce an incorrect low signal.
A problem with the circuit's power or ground path may affect the signal.
A control-module or related circuit fault is possible, but should be considered only after appropriate circuit checks.

Diagnostic Steps

Note whether the check-engine light is accompanied by reduced power, hesitation, stalling, or inconsistent accelerator response; stop driving if control or acceleration is unsafe.
With the vehicle parked safely and the ignition off, visually inspect accessible wiring and connectors associated with the throttle and accelerator-pedal position circuits for looseness, damage, corrosion, or contamination.
Check whether the code returns after recording it and any other stored codes; additional codes can help guide diagnosis, but clearing a code does not repair the cause.
If you have a compatible scan tool, observe available throttle and pedal position readings without forcing the throttle or working near moving parts. Leave electrical testing and signal interpretation to a qualified technician if you are unsure.
Use model-, year-, and engine-specific service information before attempting repairs; do not replace a sensor solely because this code is present.

When to Call a Professional

A technician can compare available throttle and pedal position scan data, inspect the circuit and connectors, and test its power, ground, and signal paths using vehicle-specific service information. The results help distinguish a wiring or connection problem from a sensor or control-module issue; the code alone is not proof of a failed part.

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Commonly Asked Questions

Does P0227 prove that the throttle or pedal sensor is bad?

No. It identifies a low input in the C sensor/switch circuit. Wiring, connectors, power or ground paths, and other circuit faults can produce the same detected condition.

Can I keep driving with P0227?

That depends on how the vehicle behaves. If acceleration is weak or unpredictable, the engine stalls, or reduced power makes driving unsafe, stop when safe and arrange an inspection.

What does the C in the code identify?

It identifies the C sensor/switch circuit designation. The exact circuit arrangement and component applicability depend on the vehicle, so use model-, year-, and engine-specific service information.

How is the cause usually distinguished?

A technician can compare available position-sensor scan data and inspect and test the relevant wiring, connectors, power, ground, and signal paths. These checks help determine whether the issue is in the sensor or elsewhere in the circuit.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.