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

Single Stage Airbags
If your vehicle has frontal airbags with single stage
deployment and your vehicle goes straight into a wall
that does not move or deform, the threshold level
is about 13 to 16 mph (20 to 25 km/h). (The threshold
level can vary, however, with specific vehicle design,
so that it can be somewhat above or below this range.)
What Makes an Airbag Inflate?
In an impact of sufficient severity, the airbag sensing
system detects that the vehicle is in a crash. 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.

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. Airbags supplement 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 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 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.
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