GMC 2006 Envoy Owner's Manual page 70

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.
The frontal airbags (driver and right front passenger) are
not intended to inflate during vehicle rollovers, rear
impacts, or in many side impacts.
Your vehicle has seat position sensors which enable 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.
1-64
Your vehicle may or may not have a roof-mounted
airbag and a rollover sensor. See Airbag System on
page 1-58. These "rollover capable" airbags are
intended to inflate in moderate to severe side crashes
or during a rollover. A roof-mounted airbag will inflate if
the crash severity is above the system's designed
"threshold level." The threshold level can vary with
specific vehicle design. Roof-mounted airbags are not
intended to inflate in frontal or near-frontal impacts,
or rear impacts. Both roof-mounted airbags will deploy
when either side of the vehicle is struck or during
a rollover.
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-mounted
airbags, inflation is determined by the location and
severity of the impact.
The airbag system is designed to work properly under a
wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough
terrain. As always, wear your safety belt. See Off-Road
Driving on page 4-19 for tips on off-road driving.