What Makes An Airbag Inflate; How Does An Airbag Restrain - GMC 2006 Envoy Owner's Manual

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 side impact
airbag, the sensing system detects that the vehicle is
about to roll over. 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 side impact 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 side impact
airbags would not help you in many types of collisions,
including many 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
side impact airbags.
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