Rank: Wiz
Rating: 88%, 5 votes
Are you trying to use your spare key to start? BMW keys have transponders in the keys which allows it to start. Its basiclly just another security system to be sure no body is poping your ignition or anything like that. I wish I knew how to tell you how to tell if your transponder in your key is working, or the transponder unit in your car is working, but I can't. Your best bet is to call the dealership to check on that.