This is as crazy as the OnStar problem. I drove the car to a wheel exchange shop in Pomona, super nice guy. Wheels look great but when I left, the air bag light was going on and off, come on stay on for several miles then go off and stay off for several miles. Now before I could get home it just stays on. Checked the owners manuel, no help. looked in my service book. Good luck with that. Any Ideas Please...

Are you saying you took your car to an auto repair shop ...then ... after getting your car back, you noticed an error light?  Did you have the car check your owners manual ... or have the car checked for codes (either at the wheel shop, or a GM dealer)?  Are you aware these cars have lots of computers on them (including TPMS - Tire Pressure Monitoring System)? 

Your situation is not crazy ... and likely can be resolved by using basic, common sense.  Check your owners manual, and check the codes!  Your wheel shop may have done something ... or ... you have a maintenance / service issue.

SUGGESTION:  Do NOT take your car to a Jiffy Lube, Pep Boys, or generic facility ... unless you want to experience generic maintenance, and generic customer service.

I did the basic checking, as much as I could think of. The wheel shop guy is former GM employee and very knowledgeable about the TPS sensor, told me they had to go back exactly like they are positioned, so they seem to work the same. I did turn off the passenger bag in the glove box and the light in the dash cycled off. My next step is to turn it back on. Now I did replace the front center spoiler, wonder if something got moved?

Wiggle the wires under seat , the light should go off

Thanks I'll give that a try. I'm out of town this weekend and I'm in the C5. I turned off the passenger side airbag and the light went out for a couple of days. Then came back on and back off.

Did wiggle the wires under the seat and light went off, only to come back on again. Tried two other times to wiggle wires no  work.

You're not crazy.  I had the same problem while I was on a cross-country trip and nothing had been changed or altered - - it would come on and off.  When I'd re-start sometimes it would stay off, sometimes not.  I asked On-Star for a diagnostic . . . no problems noted Sir.  Then I read about checking the connector under the driver's seat . . . it was secure.  A month or so later I noticed that the battery was reporting 13.6 volts . . . and then it failed (pretty good life - 8 years!).  I replaced the battery and the air bag light has stayed off since.  I had also been getting a traction control system warning but not consistently - - that too has gone away.