I was backing up from a stand still on a parking lot when the car braked extremely hard. There briefly was a message on the center dash with the word emergency on it. The message went away immediately and the car continued to work normal. My neck is still hurting hours later from the very hard brake. During the whole incident there was no other car moving and no person or other object anywhere in the path of the car. I have not yet brought the car to the dealer but will do so next week.