The electronic throttle body (ETB) is a main part of an electronic throttle control (ETC) system. The ETB controls the volume of air flowing into the engine. It features a butterfly valve which opens and closes according to a signal from the engine control unit. Instead of a traditional throttle body with an accelerator cable, Hitachi Automotive Systems Americas, Inc.’s ETB utilizes a microcomputer to control the valve opening quickly and precisely. Precision is essential to keep engine torque at a constant level when changing the air/fuel ratio. A more accurate ETB translates to improved fuel economy and emissions performance.