Chevrolet 2010 Colorado Owner's Manual page 94

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 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.
2-68
Your vehicle may or may not have roof-rail airbags. See
Airbag System on page 2-63. 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.