Can't speak for all vehicles, but mine ('10 CTS) has a procedure for programming a new RF fob if you don't have any working fobs to start from. It takes about

Can't speak for all vehicles, but mine ('10 CTS) has a procedure for programming a new RF fob if you don't have any working fobs to start from. It takes about 1/2 an hour and requires you to put the new fob in a special slot on the center console. It also requires you to activate the ignition switch on and off at some defined interval. I think the idea is that if they make it take a long time it reduces the chances of someone being able to sit there and not look suspicious.