Chevrolet silverado 2012 Owner's Manual page 102

3-30 Seats and Restraints
The vehicle may have 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.
Vehicles with dual stage airbags
also have seat position sensors
which enable the sensing system to
monitor the position of the driver
seat (all models), and on crew cab
and extended cab models the right
front passenger seat on light duty
models only. The seat position
sensor provides information that is
used to determine if the airbags
should deploy at a reduced level or
at full deployment.
The vehicle may or may not have
seat mounted side impact and
roof-rail airbags. See Airbag System
on page 3 25. Seat mounted side
impact and 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 or in a
severe frontal impact. 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 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, or if the
sensing system predicts that the
vehicle is about to roll over, or in a
severe frontal impact.
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. In a
rollover event, roof-rail airbag
deployment is determined by the
direction of the roll.