CHEVROLET 2010 Express - Manual (Page 91)

In any particular crash, no one can say whether an
airbag should have inflated simply because of the
damage to a vehicle or because of what the repair costs
were. For frontal airbags, inflation is determined by
what the vehicle hits, the angle of the impact, and how
quickly the vehicle slows down. For roof-rail airbags,
deployment is determined by the location and severity of
the side impact.
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 for the first,
second, and third rows (if equipped). See Where Are
the Airbags? on page 2-63 for more information.
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, second, and third
rows, if equipped. 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 2-65 for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
2-67