Driving at constant speed on highway, vehicle either loses acceleration and / or applies brake for short moment. Tapping the accelerator appears allow the vehicle to resume to initial intended speed. Automatic braking, not intended by the driver is a safety risk for both this and adjacent drivers. The problem has been reproduced by a dealer service center. No other agencies have inspected the vehicle’s problem. No warning lamps, messages or other symptoms evident. Dealer has had the vehicle to two weeks and has not provided a viable resolution.