The Airbag light strategy does not work like the Check Engine light regarding how long it stays on. If a fault is detected, the light is illuminated and the airbags will not deploy in a crash. If the fault goes away, the light goes out.
Most airbag systems are pretty similar in functionality. They have an airbag, airbag module and 1-3 crash detection sensors (accelerometers). Most of the newer vehicles have only 1 crash sensor located within the airbag module.
http://www.aa1car.com/library/airbag01.htm
Scroll down to the second video...lmfao