Chevrolet 2010 Impala Owner's Manual page 92

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.
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.
In addition, the vehicle has dual-stage frontal airbags.
Dual-stage airbags adjust the restraint according to
crash severity. The vehicle has electronic frontal
sensors, which help the sensing system distinguish
between a moderate frontal impact and a more severe
frontal impact. For moderate frontal impacts, dual-stage
airbags inflate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.
2-62
The vehicle has seat-mounted side impact and
roof-rail airbags. See Airbag System on page 2-56.
Seat-mounted side impact and roof-rail airbags
are intended to inflate in moderate to severe side
crashes. Seat-mounted side impact and 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 rollovers
or rear impacts. A seat-mounted side impact airbag
is intended to deploy on the side of the vehicle that is
struck. Both roof-rail airbags will deploy when either side
of the vehicle is struck.
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 seat-mounted
side impact and roof-rail airbags, deployment is
determined by the location and severity of the side
impact.