I WAS DRIVING STRAIGHT AT AROUND 40MPH ON A FOUR LANE ROAD WHEN I HEARD A LOUD BANG SIMILAR TO A GUN SHOT. SMOKE FILLED THE CABIN AND THE SEAT BELT LOCKED LOCKED UP CAUSING A CUT TO MY NECK. THE PASSENGERS SEAT BELT ALSO LOCKED UP. FORTUNATELY, MY WIFE WAS SITTING IN THE MIDDLE AND OUR TWO AND FOUR YEAR OLD DAUGHTERS WERE IN THE BACK IN THEIR CAR SEATS. I DID NOT HIT ANYTHING WITH THE TRUCK AND WE DID NOT GO OVER A SPEED BUMP OR HIT A POT HOLE. I DID NOT SLAM THE BRAKES. IT WAS A CLEAR, SUNNY DAY AND THE SEAT BELT PRETENSIONER BASICALLY EXPLODED FOR NO APPARENT REASON. TRUCK IS AT BEATY CHEVROLET NOW WHERE THEY'RE SAYING THAT ITS A 2008 AND OUT OF WARRANTY AND ALMOST $1900 TO REPAIR! SHOULDN'T THE MANUFACTURER BE RESPONSIBLE FOR REPLACING DEFECTIVE SAFETY EQUIPMENT THAT COULD CAUSE SERIOUS INJURY OR CAUSE THE DRIVER TO GET IN ACCIDENTS? THEY SAID THEY WOULD HAVE TO CALL THE MANUFACTURER ON MONDAY TO SEE IF THEY WOULD COVER THE REPAIR.