DTC P0638-00: Throttle Actuator Control Range/Performance (Bank 1): General Description
WARNING: This page is about a different car, the 2023 Kia Seltos. However, it is still accessible from the selected car via links, so may be relevant.
The Electronic Throttle Control (ETC) system consists of the throttle body, Throttle Position Sensor (TPS) 1, 2 and Accelerator Position Sensor (APS) 1, 2. TPS 1, 2 share the same source voltage and ground. The ECM/PCM controls the throttle motor to open and close the throttle valve. The TPS1 output voltage increases in proportion with the throttle valve opening angle after starting. TPS2 output voltage decreases in proportional with the throttle valve opening angle after starting. The TPS provides feedback to the ECM/PCM to control the throttle motor in response to the APS.