Reverse went on my 2001 Audi A4 Quattro. Automatic Transmission code is FAL I was driving down the freeway and all of a sudden I heard a big bang. after the bang my alternator went and I coasted till I stopped. Now it slightly catches in reverse but if I give it any gas or load it starts slipping. Just reverse, all the forward gears work fine.Could anyone tell me what could of happened and if it would need a total rebuilt transmission?