2005 GMC Envoy Owner's Manual - Page 64

For more severe frontal impacts, full deployment occurs. If the front of your vehicle goes straight into a wall that does not move or deform, the threshold level for the reduced deployment is about 9 to 16 mph (14 to 26 km/h), and the threshold level for a full deployment is about 18 to 25 mph (29 to 40 km/h). (The threshold level can vary, however, with specific vehicle design, so that it can be somewhat above or below this range.) Airbags may inflate at different crash speeds. For example: Your vehicle may or may not have a roof-mounted airbag and rollover sensor. See Airbag System on page 1-52. These "rollover capable" airbags are designed to inflate in moderate to severe side crashes or during a rollover. A side impact airbag will inflate if the crash severity is above the system's designed "threshold level." The threshold level can vary with specific vehicle design. Side impact airbags are not designed to inflate in frontal or near-frontal impacts, or rear impacts, because inflation would not likely help the occupant. 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. 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 the angle of the impact and how quickly the vehicle slows down in frontal and near-frontal impacts. For side impact airbags, inflation is determined by the location and severity of the impact. • If the vehicle hits a stationary object, the airbag could inflate at a different crash speed than if the object were moving. • If the object deforms, the airbag could inflate at a different crash speed than if the object does not deform. • If the vehicle hits a narrow object (like a pole) the airbag 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 airbag 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 because inflation would not likely help the occupants. 1-58