When pulling boat/trailer out of water, or when backing same up driveway, the engine would not respond to the gas pedal. This also happened when backing vehicle without trailer up a hill. The dealer has had the vehicle in three times and nothing was found. The dealer allegedly phoned the Ford engineers and was told to turn off the advance trac system. This did not work. I have had the car for over three years and Ford is unwilling to answer my complaint or go to further lengths to investigate. I have emailed their district office and have not received a response.