Chevy silverado 2006 lights "service air bag"

First of all you need to get this problem fixed ASAP. While the airbag light is illuminated, your SDM (Sensing and Diagnostic Module aka: the brain of your airbag system) shuts of power to the airbags. In which, if you are in an accident your airbags will not deploy while this light is illuminated. You need to take your vehicle to a GM dealership. A Tech 2 scantool is needed to retrieve the code from the SDM. Hopefully it won't be a costly repair, but is something that defineatly needs to be corrected soon. Good luck and hope all works well.