DTC P0638: Throttle Actuator Control Range/Performance: General Description

The Electronic Throttle Control (ETC) system is made of the components throttle body, Throttle Position Sensor (TPS) 1 & 2 and Accelerator Position Sensor (APS) 1 & 2. The throttle body contains the actuator, the throttle plate and the throttle position sensor (potentiometer), which are integrated in one housing. The actuator consists of a DC motor with a two-stage gear. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. And it provides feedback to the PCM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.