P257D
Engine Hood Switch Circuit Range/Performance
The hood switch is electrically intact, but its state is implausible — for example reporting hood-open while vehicle speed is rising, or rapid toggles. Usually a worn switch with high contact bounce or a misaligned hood actuator.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Worn switch with contact bounceCommon
- Misaligned hood actuatorPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Hood Switch
P257D is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.