A P0501 DTC trouble code may be caused by one or more of the following:
- The Vehicle Speed Sensor (VSS) is not reading (functioning) properly
- There is a broken/frayed wire leading to the vehicle speed sensor
- The vehicle's PCM is not correctly configured for the actual tire size on
The simplest thing to do is to reset the code and see if it comes back.
Next, check all wiring and connectors that lead to the speed sensor. The location
of the sensor depends on your vehicle. The sensor could be on the rear axle,
transmission, or perhaps the wheel
hub (brake) assembly.
If the wiring and connectors are OK, then check the voltage at the speed sensor.
Again, the exact
procedure wil depend on your make and model of vehicle.
If everything looks OK, replace the sensor.
Speed Sensor (VSS) Description and Operati