Please be advised that there is an ECM problem that affects 2005 Cobalt LS models and possibly others, there lies fault with the factory ECM that will disengage your engine, this will only happen after the vehicle has been turned off. I found this out the hard way and was without my Cobalt for a few days while a local dealership replaced the ECM. Chevy refused to compensate me for any time lost, they offered me a free lube and oil, but I told them I already opted for the oil and lube for life program.
The bulletin has gone out to the dealerships, but as far as I know, they have not informed owners of this possible problem. I'd suggest having your ECM checked out by your local dealership to avoid this hassle, don't let this happen to you.

 

Proof of this? Besides the word of a person with 2 posts?

 

The proof is that a bulletin was issued to all GM dealers (in Canada at least), other than that I'm just trying to keep people informed of what may or may not happen to their vehicle. If people wish to have their Cobalt checked out just in case, I'm leaving that choice, just some friendly advice, nothing more.
All I set out to do is save some people from an annoying thing that I had the luxury to experience.