Is it safe for me to unhook the battery on an 1997 A6 wagon, my cd on this vehicle seems to believe it will lose the tranny codes and will have to be taken to the dealer and have reinstalled. Can i do this and only lose the radio code?

 

no its not

 

Is there a reason? You will loose the key programming and the radio code, however the engine light will not reset, the best thing to do is to get a scanner and clear the code.