2003 Nissan Sentra Owner's Manual - Page 44

7. Check to make sure the child restraint is properly secured prior to each use. If the seat belt is not locked, repeat steps 3 through 6. After the child restraint is removed and the seat belt is fully retracted, the automatic locking mode (child restraint mode) is canceled. WRS0257 Front Facing - step 5 5. Before placing the child in the child restraint, use force to tilt the child restraint from side to side, and tug it forward to make sure that it is securely held in place. It should not move more than 1 inch. 6. Check that the retractor is in the automatic locking mode by trying to pull more seat belt out of the retractor. If you cannot pull any more belt webbing out of the retractor, the retractor is in the automatic locking mode. 1-38 Seats, restraints and supplemental air bag systems