DTC P0120: Throttle/Pedal Position Sensor/Switch "A" Circuit; DTC P0122: Throttle/Pedal Position Sensor/Switch "A" Circuit Low Input; DTC P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit High Input: Notes
WARNING: This page is about a different car, the 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
HINT:
This is the purpose for the "throttle position sensor".