Dual Stage Air Bags; Single Stage Air Bags - Chevrolet 2004 Express Van Owner's Manual

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 the GVWR (Gross Vehicle Weight Rating) of your
vehicle is 8600 or above, your vehicle has single stage
air bags. If the GVWR is below 8600 then your
vehicle has dual stage air bags. You can find the GVWR
on the certification label on the rear edge of the
driver's door. See Loading Your Vehicle on page 4-31
for more information.

Single Stage Air Bags

If your vehicle has frontal air bags with single stage
deployment and 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.

Dual Stage Air Bags

If your vehicle has frontal air bags with dual stage
deployment, the amount of restraint will adjust according
to the 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 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 many side impacts because inflation would
not help the occupant.
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