To provide a method for controlling an accelerator sensor signal conversion device of an electronic control throttle device of easy installation surely stopping a vehicle even if a vehicle goes into a state that an accelerator is stepped in against intention of a driver during travel of the vehicle.

This device is installed between an engine computer and an accelerator sensor of a vehicle equipped with an electronic control throttle device. Accelerator opening signal output from the accelerator sensor by stepping an accelerator pedal is output to the engine computer after attenuating the accelerator opening signal at that time when a brake is applied. Consequently, engine speed is dropped and the vehicle is safely stopped by applying the brake and serious accident can be avoided even if a floor mat is carelessly shifted and covers the accelerator pedal in such a manner that the floor mat steps in the accelerator pedal and the vehicle goes out of control.