I saw this 2x, while browsing the forum, sounds like a common problem, figure I'll chime in:
I've had this one before on my 09 Milan, The problem is in your "smart seat"! My owner's manual actually states to check for debris under the passenger seat if the airbag light is on, which I did and yippee, the light went out. It has happened a couple other times before, usually after someone moved the seat or I folded it flat. All I did is slide the seat back and forth and jiggle the wires underneath and then no more light on the next ignition cycle. Probably a loose connection, I'll need to investigate further if the problem persists.