1999 GMC Jimmy Owner's Manual - Page 16

yellowblue On two-door models with an inside mounted spare tire, the driver's side rear seat head restraint must be lifted and held upright as the seatback is raised. Otherwise, the head restraint will hit the spare tire and prevent the seatback from properly latching. Push and pull on the head restraints to check that they have locked in the upright position. If they haven't, have them fixed immediately. The rear seat head restraints are adjustable. Push the button located under the head restraint to raise or lower it. Slide the head restraint up or down so that the top of the head restraint in closest to your ears. After releasing the button, push and pull on the head restraint to make sure it's locked in place. To return the head restraints to the upright position, reach behind the seats and pull the head restraint up until it locks into position. 1-10