TL*THE CONTACT OWNS A 2006 FORD EXPLORER. WHILE DRIVING 40 MPH, THE REAR SEAT BELT BUCKLE LOOSENED WITHOUT WARNING. THE CHILD SITTING IN THE BOOSTER SEAT SLAMMED HIS FACE AGAINST THE SEAT IN FRONT OF HIM, LEAVING A SLIGHT BURN ON HIS NOSE. THE ROAD CONDITIONS WERE DRY. THE VEHICLE IS CURRENTLY AT THE CONTACT'S RESIDENCE AND HAS NOT BEEN TAKEN TO A REPAIR SHOP. THE POWERTRAIN WAS UNKNOWN. THE CURRENT AND FAILURE MILEAGES WERE 18,200.