In an impact of sufficient severity, the airbag sensing system detects that the vehicle is in a crash. For both frontal and side impact airbags, the sensing system triggers a release of gas from the inflator, which inflates the airbag. The inflator, the airbag and related hardware are all part of the airbag modules. Frontal airbag modules are located inside the steering wheel and instrument panel. For side impact airbags, the airbag modules are located in the seatback closest to the driver's and/or right front passenger's door.