Code P0502

Im getting a check engine light, took it AutoZone and a P0502 code comes up. It say its a speed sensor. Which one, anyone ever seen this. After looking up the code, it also said Vss input low. Does that mean the battery is low or the alternator is going bad? Something might be screwy in the electrical system because at the same time I noticed the temp guage was jumping around, not to mention last week the fuel gauge seem to be out of whack.

P0502 Vehicle Speed Sensor low voltage.

The vehicle speed sensor is located at the transmission output shaft ans interacts with a magnet on the shaft. The PCM detirmines vehicle speed by the number of revs of the output shaft.

did you ever fix this, you discribed exactly what my truck is doing and has the same code.

it actually shows that my truck in over heating but its just fine. the gas guage just moves around.