For 1990-2009 cars

In an impact of sufficient severity, the airbag sensing system detects that the vehicle is in a crash. In the case of a roof-mounted rollover airbag, the sensing system detects that the vehicle is about to roll over or has been in a severe frontal or side impact. The sensing system triggers a release of gas from the inflator, which inflates the airbag. The inflator, airbag, and related hardware are all part of the airbag modules inside the steering wheel and in the instrument panel in front of the right front passenger. For vehicles with roof-mounted rollover airbags, the airbag modules are located in the ceiling of the vehicle, near the side windows.

If your vehicle has a third row seat with roof-mounted rollover airbags, the airbag modules are located inside the rear-most pillar trim and above in the ceiling above the fixed rear glass.