Buick 1993 Century Owner's Manual page 39

Q :
Where is the air bag?
A:
The driver's air bag is in the middle of the steering
wheel.
Q :
When is
an
air bag expected to inflate?
A:
The air bag is designed to inflate in moderate to
severe frontal or near-frontal crashes. The air bag
will only inflate if the velocity of the impact is above
the designed threshold level. When impacting
straight into a wall that does not move or deform,
the threshold level for most GM vehicles is between
9 and 14 mph (14 and 23 km/h). However, this
velocity threshold depends on the vehicle design and
may be several miles-per-hour faster or slower. In
addition, this threshold velocity will be considerably
higher if the vehicle strikes an object such as a
parked car which will move and deform on impact.
The air bag is also not designed to inflate in
rollovers, side impacts, or rear impacts where the
inflation would provide no occupant protection
benefit.
In any particular crash, the determination of whether
the air bag should have inflated cannot be based
solely on the level of damage on the vehicle(s).
Inflation is determined by the angle
of
the impact
and the vehicle's deceleration, of which vehicle
damage is only one indication. Repair cost is not a
good indicator of whether an air bag should have
deployed.
Q :
What makes an air bag inflate?
A:
In a frontal impact of sufficient severity, sensors
strategically located on the vehicle detect that the
vehicle is suddenly stopping as a result of a crash.
These sensors complete an electrical circuit,
triggering a chemical reaction of the sodium azide
sealed in the inflator. The reaction produces nitrogen
gas, which inflates the cloth bag. The inflator, cloth
bag, and related hardware are all part of the air bag
inflator module packed inside the steering wheel.
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