Log into the new instrument cluster with VAG-COM and get the immobiliser i.d. #
and take that and the VIN # to the dealer to obtain your SKC #. You will also need to do the same procedure for the old cluster as well, so if I remember correctly you will need 2 unique SKC's, one for each cluster. Then go to the Ross-Tech website and follow the appropriate instructions. Make sure you have all the keys for the car including the valet key for the key matching portion.
What he said. While swapping ECU's I came upon the same problem even though the ECU #'s were the same. The dealer could fix it but I had no luck getting the chip to work with my car. Im glad though cus I got apr'd instead or Neuspeed'd. Good luck.