MY AIR BAG DID NOT ACTIVATE AND IN A DIRECT FRONT END COLLISION. THE SUN SETTING BLINDED ME AND I HIT DIRECTLY THE REAR OF THE CAR IN FRONT OF ME AND IT'S AIRBAG DEPLOYED AND THE CHAIN REACTION OF THE TWO CARS IN FRONT OF THE CAR I HIT AIRBAGS DEPLOWED. GM SAID MY AIRBAG WAS NOT DEFECTIVE AND I ASKED TO HAVE IT CHECKED TWO TIMES. IT SHOULD HAVE DEPLOYED AND IT DID NOT. I WAS NOT WEARING A SEAT BELT AND I SUFFERED HEAD INJURIES. I SOLD TRUCK BECAUSE I DID NOT WANT TO DIE NEXT FAILURE.