Originally Posted by
GraphiteGhost
I mentioned, I believe any crossfire FOB circuit board (2004 - 2008) when placed into the FOB body (undamaged) will allow the lock/unlock (providing the rest of the system for lock/unlock works). 
Sorry that's not right. The RF-Part (the circuit board) of the Keyfob has stored a roling code who have to match to the code of the transponder. So only change the circuit board will not work. If you know in what chip the code is stored you can desolder it from the old circuit board and resolder it to the new board.
I don't know where this code is stored.