So is there any definitive solution to this problem? We bought a '13 C-Max SEL last Friday and experienced this car-shuts-off-when-backing-up problem repeatedly through the weekend. I don't think it can be the normal functioning of the hill brake assist feature because it cuts off the power steering too, and you need to be able to turn the wheels when starting up on a hill. Also, while we do have a slanty driveway, it didn't happen right at the rest spot, but 10 or so feet away down at the bottom as we were turning the wheel, as well as in flat parking lots. I've taken the C-Max back to the dealer's service center and they gave me a rental, but if the cause/solution is known I'd like to pass it on to them because they seemed befuddled - not a car they have much experience with yet. Glad to find this thread though. My wife - who is doing most of the driving in this car, and to whom it was happening - worried until we found it that she was just doing something stupid, even though she never had that problem with our old car.