EXT Service Airbag light

My service airbag light came on yesterday and won't go off. Is there a sensor that needs checking? Will the airbag still work? Will the dealer cover this under extended warranty since this is a safety item?

Welcome to AF, been to Pensacola Naval Musem a few times when I stay in Destin. The SIRS must be scanned with a special scanner for a diagnosis, no the system is disabled when the lite is on. No mention of year but Cadillac usually had a 4 year 50k warranty.

Your vehicle will require a scan tool for the proper diagnosis, but here's a site that will explain everything you need to know about airbag lights and resetting the system.
http://www.airbagsolutions.com/

This website gives you the procedure for diagnosing and resetting airbag lights. See if your car is listed here. Although it’s a pay site ($14.95/day), it’s a lot cheaper than going to the dealer
http://www.airbagsolutions.com/vehicles_list.aspx

On most vehicles, the airbag light should come on for @6 seconds, and then go off if the system is working properly. If there is a fault or a problem in the system, the light will remain illuminated, or flash continuously. If the airbag light does not work properly, some vehicles have an audible tone that sounds indicating a problem with the airbag light system. When the light is on (or the tone is sounding), the airbag will NOT deploy, even in an accident.
Once you know the code, you can most likely repair it yourself. There are fairly easy procedures that most people are capable of repairing.
Airbagsolutions.com has the fault code charts to tell you what is wrong and how to fix it!

Some vehicle manufacturers accommodate systems without a scanner (like Toyota, Lexus, Nissan, Infinity, Honda, Acura, Ford, Lincoln, Mazda & Mercury) .
Most all other vehicles require a scan tool for the diagnosis.

Check out these websites also for more info on airbag systems and the light.
http://blog.airbagsolutions.com/archive/2007/11/18/why-is-my-airbag-light-on.what-should-i-do.aspx

Lastly, check your vehicle for recalls through this link also:
http://www.airbagsolutions.com/nhtsa.aspx

My service airbag light came on yesterday and won't go off. Is there a sensor that needs checking? Will the airbag still work? Will the dealer cover this under extended warranty since this is a safety item?

The "service air bag" warning light went on when I inserted a maglite flashlight at the bottom right side of the driver seat. That caused a wire clip to be unplugged. I damaged the 'clip stop' but was able plugged it back and the warning light went off. You might have accidentally unplugged that wire clip.