GMC 2007 Yukon XL Owner's Manual page 97

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 a seat position sensor which
enables the sensing system to monitor the
fore and aft position of the driver'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.
Your vehicle may or may not have a roof-mounted
rollover airbags and a rollover sensor. See Airbag
System on page 90. These "rollover capable"
airbags are intended to inflate in moderate to
severe side crashes, during a rollover or in a severe
frontal impact. A roof-mounted rollover 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 rear impacts.
Both roof-mounted rollover airbags will deploy when
either side of the vehicle is struck or during a
rollover, 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 roof-mounted rollover airbags,
inflation is determined by the location and severity
of the impact or a rollover event.
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 356 for tips on
off-road driving.
97