What Makes An Airbag Inflate; How Does An Airbag Restrain - GMC 2009 Sierra 1500 Crew Cab Owner's Manual

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 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 impact
more evenly over the occupant's upper body, stopping
the occupant more gradually. Roof-rail airbags distribute
the force of the impact more evenly over the occupant's
upper body.
Rollover capable roof-rail airbags are designed to help
contain the head and chest of occupants in the outboard
seating positions in the first and second rows. The
rollover capable roof-rail airbags are designed to help
reduce the risk of full or partial ejection in rollover events,
although no system can prevent all such ejections.
But airbags would not help in many types of collisions,
primarily because the occupant's motion is not
toward those airbags. See When Should an Airbag
Inflate? on page 1-77 for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
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