P0501
Vehicle Speed Sensor "A" Range/Performance
The VSS signal is present but inconsistent — either values jump implausibly or the sensor reports a speed inconsistent with engine RPM in gear. Often a damaged reluctor ring or a sensor with degraded magnetic response.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Sensor signal intermittentCommon
- Reluctor tooth damagedLess likely
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Vehicle Speed Sensor
- Reluctor Ring
P0501 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.