The Electronic Throttle Control(ETC) system which is composed of throttle body, the Throttle Position Sensor(TPS) 1&2 and the Accelerator Position Sensor(APS) 1&2 controls the mass of airflow by driver's intention. The throttle valve opening is controlled by throttle motor which is controlled by the PCM. the TPS is a variable resistance and its value is cahnged by open angle of throttle valve.