When Should An Air Bag Inflate; Dual Stage Air Bags; Single Stage Vs. Dual Stage Air Bags - Chevrolet 2003 Silverado 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."
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.
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 4-22 for more tips on off-road driving.

Single Stage vs. Dual Stage Air Bags

Depending on the weight of your vehicle you will
have either "Single Stage Air Bags" or "Dual Stage Air
Bags". Vehicles that have a passenger sensing
system also have dual stage air bags. If the rearview
mirror in your vehicle has a passenger air bag
status indicator printed on it, your vehicle has the
passenger sensing system and therefore, it has dual
stage air bags. If the rearview mirror in your vehicle does
not have a passenger air bag status indicator printed
1-68
on it, then your vehicle does not have the passenger
sensing system and it has single stage air bags.
See Passenger Air Bag Status Indicator on page 3-40
or Passenger Sensing System on page 1-76 .

Dual Stage Air Bags

If your vehicle has frontal air bags with dual stage
deployment, the amount of restraint will adjust 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
does not move or deform, the threshold level for the
reduced deployment is about 10 to 16 mph
(16 to 25 km/h), and the threshold level for a full
deployment is about 20 to 25 mph (32 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 air bag is not designed to inflate in
rollovers, rear impacts, or in many side impacts because
inflation would not help the occupant.