I USED THE BUTTON ON MY KEY FOB TO OPEN THE POWER LIFT GATE. ONCE THE DOOR WAS OPEN ENOUGH I STARTED TO PLACE TWO ITEMS N THE REAR OF THE MINIVAN. RATHER THAN STOPPING AT THE TOP WHEN OPEN, THE DOOR STUTTERED A MOMENT AT THE FULLY OPEN POSITION AND THEN SLAMMED FORCIBLY SHUT ON MY HEAD. THE BLOW NEARLY KNOCKED ME OUT. I WAS NOT ABLE TO MANUALLY OPEN THE DOOR. EACH ATTEMPT TO OPEN THE DOOR WITH THE KEY FOB HAD THE SAME TYPE OF RESULT. THE DOOR WOULD REACH THE TOP, STUTTER AND THEN FORCIBLY SLAM SHUT. I AM GLAD IT WAS ME AND NOT MY WIFE OR DAUGHTER. I DID NOT SEEK MEDICAL ATTENTION, BUT DID EXPERIENCE DIZZINESS FOR SEVERAL HOURS AFTERWARDS.