What Makes An Airbag Inflate; How Does An Airbag Restrain - GMC 2007 Sierra Owner's Manual

The threshold level can vary, however, with
specific vehicle design, so that it can be somewhat
above or below this range. Vehicle's with dual
stage airbags also have a sensor which enables
the sensing system to monitor the position of
the driver seat. The seat position sensor provides
information which is used to determine if the
airbags should deploy at a reduced level or at full
deployment.
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 roof-mounted rollover
airbag, the sensing system detects that the
vehicle is about to roll over or has been in a severe
frontal impact or a moderate to severe side
impact. 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 rollover 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.
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
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 rollover airbags would not help you
in many types of collisions, including many
frontal or near frontal collisions, and rear impacts.
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 vehicles
with roof-mounted rollover airbags.
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