DTC P0122: Throttle Position Sensor 1 Signal Circuit Low Input: General Description

The Electronic Throttle Control (ETC) system consists of the Throttle body assembly, Throttle Position Sensor (TPS) TPS1/TPS2 and Accelerator Position Sensor (APS) APS1/APS2. TPS1 and TPS2 share the same source voltage and ground. The ECM/PCM controls the throttle motor to open and close the throttle valve. TPS1 output voltage increases in proportion with the throttle valve opening after starting. TPS2 output voltage decreases in proportion 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 output voltage.