What Makes An Airbag; Inflate; How Does An Airbag; Restrain - GMC 2011 Yukon XL Denali Owner's Manual

3-38 Seats and Restraints
Roof-rail airbags are not intended to
inflate in rear impacts. A seat
mounted side impact airbag is
intended to deploy on the side of the
vehicle that is struck. Both roof-rail
airbags will deploy when either side
of the vehicle is struck or if the
sensing system predicts that the
vehicle is about to roll over, or in a
severe frontal impact.
In any particular crash, no one
can say whether an airbag should
have inflated simply because of
the damage to a vehicle or because
of what the repair costs were.
For frontal airbags, inflation is
determined by what the vehicle hits,
the angle of the impact, and how
quickly the vehicle slows down.
For seat mounted side impact and
roof-rail airbags, deployment is
determined by the location and
severity of the side impact. In a
rollover event, roof-rail airbag
deployment is determined by the
direction of the roll.

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 and deploy. The inflator,
the airbag, and related hardware are
all part of the airbag module.
Frontal airbag modules are located
inside the steering wheel and
instrument panel. For vehicles with
seat mounted side impact airbags,
there are airbags modules in the
side of the front seatbacks closest
to the door. For vehicles with
roof-rail airbags, there are airbag
modules in the ceiling of the vehicle,
near the side windows that have
occupant seating positions.

How Does an Airbag

Restrain?

In moderate to severe frontal or
near frontal collisions, even belted
occupants can contact the steering
wheel or the instrument panel. In
moderate to severe side collisions,
even belted occupants can contact
the inside of the vehicle.
Airbags supplement the protection
provided by safety belts. Frontal
airbags distribute the force of the
impact more evenly over the
occupant's upper body, stopping the
occupant more gradually. Seat
mounted side impact and roof-rail
airbags distribute the force of the
impact more evenly over the
occupant's upper body.