What Makes An Airbag Inflate; How Does An Airbag Restrain - GMC 2005 Envoy Owner's Manual

The airbag system is designed to work properly under
a wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough
terrain. As always, wear your safety belt. See Off-Road
Driving with Your Four-Wheel-Drive Vehicle on
page 4-15 for tips on off-road driving.
What Makes an Airbag Inflate?
In an impact of sufficient severity, the airbag sensing
system detects that the vehicle is in a crash. In the
case of a "rollover capable" roof-mounted airbag, the
sensing system detects that the vehicle is about to
roll over. For both frontal and roof-mounted airbags,
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 airbags, the airbag modules are
located in the ceiling of the vehicle, near the side
windows.

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. The airbag supplements the protection
provided by safety belts. Airbags distribute the force of
the impact more evenly over the occupant's upper
body, stopping the occupant more gradually. But the
frontal airbags would not help you in many types
of collisions, including rollovers, rear impacts, and
many side impacts, primarily because an occupant's
motion is not toward the airbag. Roof-mounted airbags
would not help you in many types of collisions,
including frontal or near frontal collisions, and rear
impacts, primarily because an occupant's motion is
not toward those airbags. Airbags should never
be regarded as anything more than a supplement to
safety belts, and then only in moderate to severe frontal
or near-frontal collisions for the driver's and right front
passenger's frontal airbags, and only in moderate
to severe side collisions or rollovers for the roof-mounted
airbags.
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