The ESC is the acronym for Electronic Stability control. The ESC is a braking system that combines the functions of a brake servo unit and the ABS(Antilock Braking System) equipment including ESP(Electronic Stability Program). The ESC is a technology that improves the safety of a vehicle's stability by detecting and reducing loss of traction. When ESC detects loss of a steering control, it automatically applies the brakes to help steer the vehicle where the driver intends to go. Braking is automatically applied to wheels individually. Driver can inhibit the ESP control by ESP switch. When switch signal sends into the HECU, the ESP warning lamp turns "ON" and the ESP control is stopped and if the next switch signal is inputted again, the ESP control is ready. This function is used for sporty driving or vehicle inspection.