Hummer 2008 H2 - Manual (Page 73)

When Should an Airbag Inflate?
Frontal airbags are designed to inflate in moderate to
severe frontal or near-frontal crashes to help reduce the
potential for severe injuries mainly to the driver’s or
right front passenger’s head and chest. However, they
are only designed to inflate if the impact exceeds a
predetermined deployment threshold. Deployment
thresholds are used to predict how severe a crash is
likely to be in time for the airbags to inflate and
help restrain the occupants.
Whether your frontal airbags will or should deploy is not
based on how fast your vehicle is traveling. It depends
largely on what you hit, the direction of the impact,
and how quickly your vehicle slows down.
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 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.
Thresholds can also vary with specific vehicle design.
Frontal airbags are not intended to inflate during vehicle
rollovers, rear impacts, or in many side impacts.
Your vehicle has roof-rail airbags. See Airbag System
on page 1-64. Roof-rail airbags are intended to inflate in
moderate to severe side crashes. In addition, these
roof-rail airbags are intended to inflate during a rollover.
Roof-rail airbags will inflate if the crash severity is
above the system’s designed threshold level. The
threshold level can vary with specific vehicle design.
Roof-rail airbags are not intended to inflate in frontal
impacts, near-frontal impacts, or rear impacts. Both
roof-rail airbags will deploy when either side of
the vehicle is struck, or if the sensing system predicts
that the vehicle is about to roll over.
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. For frontal airbags, inflation is determined by
what the vehicle hits, the angle of the impact, and how
quickly the vehicle slows down. For roof-rail airbags,
deployment is determined by the location and severity of
the side impact. In a rollover event, roof-rail airbag
deployment is determined by the direction of the roll.
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