Guage Failure and warning lights

[CamKen]

As I was coming home today the guages, power steering, windows and lights just quit while driving on the freeway. The car stumbled a bit and then everything died. This is the second time this has happened. I had the dealer check it and they said it was the ignition coils and an almost dead battery. I replaced the battery and had them do a software upgrade but the problem is still there. Right now the message window reads airbag service urgent. Any ideas? Thanks!