What does it mean when the warning light says check airbag?

It probably means the muffler nut is loose.

There's something wrong with the airbag (SRS) system. Best to let your local Chevrolet Dealer fix it. Messing with the airbag system can be deadly if you're not familiar with the system! Hope that helps! Jim

I agree that its not a good idea to go digging around for the problem if you don't know what you're doing. However, for guidance, the clock spring in the steering column wears out and is fairly easily replaced, even by a do it yourselfer if you're careful and do your homework first. I've also read that there are some electronics and electrical connections under the passenger seat that can cause problems but that's just what I've heard. My air bags failed a couple of years ago on my Cobalt and my mechanic traced it to the clockspring but said there could be additional problems, but until the clockspring is replaced he has no way of trouble shooting it further. It's on my to-do list, but obviously hasn't made it to the top yet.