2003 GMC Sonoma Owner's Manual - Page 60

5. Pull the rest of the lap belt all the way out of the retractor to set the lock. 6. To tighten the belt, feed the shoulder belt back into the retractor while you push down on the child restraint. If you are using a forward-facing child restraint, you may find it helpful to use your knee to push down on the child restraint as you tighten the belt. 7. Push and pull the child restraint in different directions to be sure it is secure. 1-53