what do these code mean?

A P0501 is a fault with the vehicle speed sensor. How well does your Speedometer work? A P0116 is a coolant temperature sensor fault, very very common on VW, just get the updated sensor, it costs about $10. I would do the same with the Speed Sensor, then clear the codes and drive the car for about 2-3 days in city and freeway conditions. Then check the codes again. This is the procedure I use on VWs, I do Emissions Diagnosis and Repair in CA.