after water affected my current one i got one off ebay for cheap cheap

plugged car into vag-com and it currently has no errors none even in certl locking area. So im thinking it must of just been a short but because i took the unit out it needs to be re-synced?
Currently the keys open doors from the locks but not from the remote thob, is it time to take to audi to get them to programe it up?