Chevrolet 2002 Astro Owner's Manual page 38

When should an air bag inflate?
An air bag is designed to inflate in a moderate to severe
-
frontal or near frontal crash. The air bag will inflate
only if the impact speed is above the system's designed
"threshold level." If your vehicle goes straight into a
wall that doesn't move or deform, the threshold level is
about 9 to 16 mph (14 to 26 km/h). The threshold level
can vary, however, with specific vehicle design, so that
it can be somewhat above or below this range. If your
vehicle strikes something that will move or deform,
such as a parked car, the threshold level will be higher.
The air bag is not designed to inflate in rollovers, rear
impacts, or in many side impacts because inflation
would not help the occupant.
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 how quickly the vehicle slows down
-
in frontal or near frontal impacts.
What makes an air bag inflate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. The sensing
system triggers a release of gas from the inflator, which
inflates the air bag. The inflator, air bag and related
hardware are all part of the air bag modules inside the
steering wheel and in the instrument panel in front of
the right front passenger.
How does an air bag restrain?
In moderate to severe frontal or near
even belted occupants can contact the steering wheel or
the instrument panel. Air bags supplement 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 many side impacts,
primarily because an occupant's motion is not toward
those air bags. 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.
-
frontal collisions,
1-31