Chevrolet 2006 Express Van Owner's Manual page 76

Frontal airbags may inflate at different crash speeds.
For example:
•
If the vehicle hits a stationary object, the airbags
could inflate at a different crash speed than if the
vehicle hits a moving object.
•
If the vehicle hits an object that deforms, the airbags
could inflate at a different crash speed than if the
vehicle hits an object that does not deform.
•
If the vehicle hits a narrow object (like a pole) the
airbags could inflate at a different crash speed
than if the vehicle hits a wide object (like a wall).
•
If the vehicle goes into an object at an angle the
airbags could inflate at a different crash speed
than if the vehicle goes straight into the object.
The frontal airbags (driver and right front passenger) are
not intended to inflate during vehicle rollovers, rear
impacts, or in many side impacts.
In any particular crash, no one can say whether an
airbag should have inflated simply because of the
damage to a vehicle or because of what the repair costs
were. Inflation is determined by what the vehicle hits,
the angle of the impact, and how quickly the vehicle
slows down in front or near-frontal impacts.
1-70
If the GVWR (Gross Vehicle Weight Rating) of your
vehicle is 8,500 lb (3 855 kg) or above, your vehicle
has single stage airbags. If the GVWR is below 8,500 lb
(3 855 kg) then your vehicle has dual stage airbags.
You can find the GVWR on the certification label on the
rear edge of the driver's door. See Loading Your
Vehicle on page 4-30 for more information.
Single Stage Airbags
If your vehicle has frontal airbags with single stage
deployment and your vehicle goes straight into a wall
that does not 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.)
Dual Stage Airbags
If your vehicle has frontal airbags with dual stage
deployment, the restraint will adjust according to the
crash severity. Your vehicle is equipped with electronic
frontal sensors which help the sensing system
distinguish between a moderate and a more severe
frontal impact. For moderate frontal impacts, these
airbags inflate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.