GMC 1996 Sierra Owner's Manual page 32

In
any particular crash, no one can say whether an air
bag should have inflated simply because of the damage
to a vehicle or because of what the repair costs were.
Inflation is determined by the angle of the impact and
the vehicle's deceleration. Vehicle damage is only one
indication of this.
The air bag system is designed to work properly under a
wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough terrain.
As always, wear your safety belt. See "Off-Road
Driving" in the Index for more tips on off-road driving.
What makes an air bag inflate?
In a frontal or near-frontal impact of sufficient severity,
the air bag sensing system detects that the vehicle
is
suddenly stopping as a result of a crash. The sensing
system triggers
a
chemical reaction of the sodium azide
sealed in the inflator. The reaction produces nitrogen
gas, which inflates the air bag. The inflator, air bag and
related hardware are all part of the air bag module
packed inside the steering wheel.
How does an air bag restrain?
In moderate to severe frontal or near-frontal collisions,
even belted occupants can contact the steering wheel.
The air bag supplements the protection provided by
safety belts. Air bags distribute the force of the impact
more evenly over the occupant's upper body, stopping
the occupant more gradually. But air bags would not
help you in many types of collisions, including
rollovers, rear impacts and side impacts, primarily
because an occupant's motion is not toward the air bag.
Air bags 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.
What will you see after an air bag inflates?
After the air bag inflates, it quickly deflates. This occurs
so quickly that some people may not even realize the air
bag inflated. Some components of the air bag module in
the steering wheel hub will be hot for a short time. The
part of the bag that comes into contact with you may be
warm, but it will never be too hot to touch. There will be
some smoke and dust coming from vents in the deflated
air bag. Air bag inflation will not prevent the driver
from seeing or from being able to steer the vehicle, nor
will it stop people from leaving the vehicle.
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