OBD-II Code P2122 is defined as a Throttle/Pedal Position Sensor/Switch "D" Circuit Low
The electronic throttle control system (ETCS) controls the throttle valve opening. When the driver presses the accelerator pedal, the Accelerator Pedal Position Sensor (APP) sends a signal to the engine's control module (PCM) telling the PCM how much power the driver is requesting from the engine. The PCM then commands the throttle plate to open accordingly. If the PCM detects the APP Sensor is not changing appropriately when the accelerator pedal is depressed or released, the PCM will set code P2122. The PCM may also put the engine into "limp home mode", limiting the available power from the engine to prevent unwanted acceleration.