What Makes An Air Bag Inflate - GMC Envoy 2003 Owner's Manual

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 12 to 16 mph
(19 to 26 km/h), and the threshold level for a full
deployment is about 16 to 25 mph (26 to 40 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.
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 with Your Four-Wheel-Drive Vehicle on
page 4-15 for tips on off-road driving.
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.
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