P0501Vehicle Speed Sensor A Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- The vehicle speed signal A comes, depending on the maker, from a sensor on the gearbox, the transmission output speed, the wheel speeds via ABS/ESP or a CAN message; CARB explicitly names it as an input to be monitored. P0501 means the signal is present but does not fit the driving state or lies outside the physically possible range. Saab's Trionic T5 sets it above 270 km/h; other makers typically compare it with engine speed times gear ratio, wheel speeds or the transmission output speed. GM's 2018 tables and Ford do not use P0501 (GM: P0503, Ford: P0500). Cruise control is then disabled.
- What you may notice
- Check engine light on
- Speedometer dead or jumping
- Cruise control not working
- Automatic shifts harshly or wrongly
- Likely causes
- LikelyWheel speed sensor or tone ring damaged or dirty (ABS source)
- PossibleWrong tyre size, axle ratio or coding
- PossibleSensor with weak signal or damaged tone wheel
- RareInterference from damaged shielding or ground
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.