Audi 1.8T p0501, p1603

[Granite A4]

So I bought a car cheap and knew it would have some issues. Rebuilt title and motor has been swapped. It is the ATW 1.8. I cleared the codes originally so that I started fresh and could determine what was going on. After clearing it doesn't take long for the CEL to come on with p0501 - vehicle speed sensor A range/performance. But then it will go away and if you scan the car you get a p1603 - internal module malfunction. So I'm just curious if anyone knew which module to look at? No ABS or BRAKE light. And I have cleared multiple times to get the same result. I read a lot of posts dealing with 1603 but everyone mentioned having a light on and I have no lights. Thanks for any help

[Granite A4]

I have a new code. P0507 but the car doesn't seem to be idling high. It reads 900rpm steady by the tach, but when I plug in the little pocket scanner I have it says it is at 1720rpm? There is no way it is actually that high so something is causing it to "think" it's high. Any ideas?