2012 Buick LaCrosse Owner Manual - Page 84

3-26 Seats and Restraints The vehicle has seat-mounted side impact airbags and roof-rail airbags. See Airbag System on page 3‑22. Seat-mounted side impact and roof-rail airbags are intended to inflate in moderate to severe side crashes depending on the location of the impact. In addition, these roof‐rail airbags are intended to inflate during a rollover or in a severe frontal impact. Seat-mounted side impact and roof-rail airbags will inflate if the crash severity is above the system's designed threshold level. The threshold level can vary with specific vehicle design. Roof‐rail airbags are not intended to inflate in rear impacts. A seat-mounted side impact airbag is intended to inflate on the side of the vehicle that is struck. Both roof‐rail airbags will inflate when either side of the vehicle is struck or if the sensing system predicts that the vehicle is about to roll over on its side, or in a severe frontal impact. In any particular crash, no one can say whether an airbag should have inflated simply because of the vehicle damage or repair costs. Frontal airbags may inflate at different crash speeds depending on whether the vehicle hits an object straight on or at an angle, and whether the object is fixed or moving, rigid or deformable, narrow or wide. Thresholds can also vary with specific vehicle design. Frontal airbags are not intended to inflate during vehicle rollovers, rear impacts, or in many side impacts. In addition, the vehicle has dual-stage frontal airbags. Dual-stage airbags adjust the restraint according to crash severity. The vehicle has electronic frontal sensors, which help the sensing system distinguish between a moderate frontal impact and a more severe frontal impact. For moderate frontal impacts, dual-stage airbags inflate at a level less than full deployment. For more severe frontal impacts, full deployment occurs. What Makes an Airbag Inflate? In a deployment event, the sensing system sends an electrical signal triggering a release of gas from the inflator. Gas from the inflator fills the airbag causing the bag to break out of the cover. The inflator, the airbag, and related hardware are all part of the airbag module. For airbag location, see Where Are the Airbags? on page 3‑24.