I recently purchased my 2012 Grand Cherokee. It is having the same problem. Just does not want to start. I've been to the dealer twice. They keep saying they don't find anything wrong. After some internet research, I am finding this is a common problem and it could be an issue with the tipm. Chrysler, apparently, is trying to keep this quiet. There are other very serious issues as well. Most importantly, the engine stopping while driving. I'm very nervous.