Pontiac 2003 Bonneville Owner's Manual page 59

If the front of your vehicle goes straight into a wall
that doesn't move or deform, the threshold level
for the reduced deployment is about 10 to 16 mph
(18 to 26 km/h), and the threshold level for a full
deployment is about 18 to 24 mph (29 to 38.5 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 driver's and right front passenger's frontal
air bags are not designed to inflate in rollovers, rear
impacts, or in many side impacts because inflation
would not help the occupant.
Your vehicle may or may not have a side impact air
bag. See Air Bag Systems in the Index. Side impact air
bags are designed to inflate in moderate
to
severe
side crashes. A side impact air bag will inflate if
the crash severity is above the system's designed
'threshold level'. The threshold level can vary with
specific vehicle design. Side impact air bags are not
designed to inflate in frontal or near-frontal impacts,
rollovers or rear impacts, because inflation would not
help the occupant. A side impact air bag will only deploy
on the side of the vehicle that is struck.
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.
For frontal air bags, inflation is determined by the angle
of the impact and how quickly the vehicle slows down
in frontal and near-frontal impacts. For side impact
air bags, inflation is determined by the location
and severity of the impact.
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. For
both frontal and side impact air bags, the sensing
system triggers a release of gas from the inflator, which
inflates the air bag. The inflator, the air bag and
related hardware are all part of the air bag modules.
Frontal air bag modules are located inside the steering
wheel and instrument panel. For vehicles with side
impact air bags, the air bag modules are located in the
seatback closest to the driver's and/or right front
passenger's door.
How Does an Air Bag 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. 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.
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