The contact owns a 2021 Ford Mustang Mach-E. The contact stated that while driving at an undisclosed speed and the brake pedal was depressed, the vehicle did not slow down as intended, and crashed into another vehicle. The contact sustained neck, head, and arm injuries. Medical attention was needed. A police report was filed. The vehicle was towed to a body shop. The manufacturer was not notified of the failure. The failure mileage was approximately 46,140.