GM 2002 Automobile User Manual


 
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When should an air bag inflate?
The driver’s and right front passenger’s frontal air bags
are designed to inflate in moderate to severe frontal or
near
-frontal crashes. But they are designed to inflate
only if the impact speed is above the system’s designed
“threshold level.”
In addition, your vehicle has “dual stage” frontal air
bags, which adjust the amount of restraint according
to crash severity. For moderate frontal impacts, these
air bags inflate at a level less than full deployment.
For more severe frontal impacts, full deployment
occurs. 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.
The 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, air bag and related hardware
are all part of the air bag modules inside the steering
wheel, instrument panel and the side of the front
seatbacks closest to the door.