2004 SIENNA XLE LIMITED -- ELECTRIC SLIDING/REAR DOOR ON DRIVER SIDE CLOSES BY ITSELF WHEN PARKED FACING DOWN INCLINE. DEALER DIAGNOSED FAULTY 'DOOR CHECK' BUT REFUSED TO REPAIR UNDER WARRANTY. THERE IS A TSB FOR FRONT DOOR 'DOOR CHECK' BUT NOT REAR SLIDING DOOR. THIS ISSUE IS A SAFETY CONCERN, AS PASSENGERS COULD BE PINNED IF DOOR WERE TO CLOSE UNEXPECTEDLY. *TR