2010 GMC Acadia Owner's Manual - Page 81

Seats and Restraints Shoulder Belt Height Adjuster The vehicle has a shoulder belt height adjuster for the driver and right front passenger seating positions. Adjust the height so that the shoulder portion of the belt is centered on the shoulder. The belt should be away from the face and neck, but not falling off of the shoulder. Improper shoulder belt height adjustment could reduce the effectiveness of the safety belt in a crash. 3-27 Safety Belt Pretensioners This vehicle has safety belt pretensioners for the front outboard occupants. Although the safety belt pretensioners cannot be seen, they are part of the safety belt assembly. They can help tighten the safety belts during the early stages of a moderate to severe frontal, near frontal, or rear crash if the threshold conditions for pretensioner activation are met. And, for vehicles with side impact airbags, safety belt pretensioners can help tighten the safety belts in a side crash or a rollover event. Pretensioners work only once. If the pretensioners activate in a crash, they will need to be replaced, and probably other new parts for the vehicle's safety belt system. See Replacing Safety Belt System Parts After a Crash on page 3‑31. To move it down, push down on the button (A) and move the height adjuster to the desired position. You can move the height adjuster up by pushing up on the shoulder belt guide. After the adjuster is set to the desired position, try to move it down without pushing the button to make sure it has locked into position.