GMC 2007 Canyon Owner's Manual page 70

Your vehicle has seat position sensors which enables
the sensing system to monitor the position of the driver's
seat and the right front passenger's seat. Seat position
sensors provide information that is used to determine
if the airbags should deploy at a reduced level or at
full deployment.
In addition, your vehicle has dual-stage frontal airbags.
Dual-stage airbags adjust the restraint according to
crash severity. Your 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.
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Your vehicle may or may not have roof-rail airbags.
See Airbag System on page 1-60. Roof-rail airbags are
intended to inflate in moderate to severe side crashes.
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, rollovers, or rear impacts.
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 roof-rail airbags, deployment
is determined by the location and severity of the side
impact.