2001 Cadillac Deville Ignition

First determine if there are any theft related fault codes. Then check for a start signal on the wire to the starter. If there is no start signal, then it would need diagnosed to see if a valid theft password is being sent when the ignition is turned.

Chances are we won't be hearing from that person, it was back in September and they never brought closure.

So your Deville occasionally won't start. First be certain that the key is not being rolled to start too quickly. It takes a second or two for the theft to validate. The next check would be, when the fault occurs, to be checking the start signal wire to see if a signal is being sent. If there is a signal and it won't turn over, it needs a starter. It would also be a good idea to check codes, and see if there are any in history that may relate.