I am sorry that I did not read all of the post but this looks like the area of the problem that I am having. When I let off of the gas pedal and cost for about 1/4 mile I will here a vibrating type of noise (minus the vibration, just that type of noise) and the car will just shut off. I can turn the key off and reset it and it will start right up again. I explained this to my dealer and nothing was a definite answer and I did not want to have to pay for diagnostic time so it was left that I drive the car until it stops completely. I think it is time for another visit to the dealership.