I did a 2004 passat with a used ABS Module, had difficulty at first,  I copied the right coding number from original module but I was using wrong log in code and it would't take it,  It worked after log in was changed, I was using VCDS by the way.  Don't know if same applies to a 2008 vehicle but go to Ross Tech Wiki and try to generate a different log in code by selecting different options and see if it takes it.