With increasing innovations in the field of Automotive Electronics, X – by wire, is becoming popular across the world. It is a system, which gets input from the driver as communication signal or electrical signal rather than the mechanical input. Mechanical linkages are not used which improves the life of the system. Brake by wire uses sensor signals from the driver to brake the vehicle. It uses sensors like Brake pedal sensor, Vehicle speed sensor. The input from the sensor is given to the ECU, which processors, the information understanding the situation and gives the output to the brakes. The brake force depends on the Speed of the vehicle, Pedal travel, Speed of pedal travel, brake pad wear. The scope of this RESEARCH includes, design and fabrication of Brake Assist System using Brake by wire technology. The Microcontroller controls the actions of the brake on the vehicle. X – by wire is a general term used to denote controlling of vehicle by wire method (Brake by wire, Drive by wire, Steer by wire.