Thats a massive coincidence this happened to you when getting sportlines fitted as well . . . . whats the chances of that? If you search you might find the thread.
The only other person i know of that this has happened to was when they crashed the car and the sensor failed then.
I could be wrong and i hope its a simpler fix but I have a feeling this is the same issue.
VW will want over £800 for a reconditioned unit on an exchange basis
. I bought a used one for £150 and ACR (north east vag specialist) installed it for £125.
Good luck