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

3-32 Seats and Restraints
The seat position sensor provides
information that is used to determine
if the airbags should deploy at a
reduced level or at full deployment.
The vehicle may or may not have
seat mounted side impact airbags.
The vehicle has roof-rail airbags.
See Airbag System on page 3 26.
Seat mounted side impact airbags
and roof-rail airbags are intended to
inflate in moderate to severe side
crashes. In addition, these roof-rail
airbags are intended to inflate
during a rollover or in a severe
frontal impact. Seat mounted side
impact airbags 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 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