DTC P0510: Throttle Position Switch - Closed Position: Description
WARNING: This page is about a different car, the 2002 Nissan Pathfinder and 2002 Infiniti QX4. However, it is still accessible from the selected car via links, so may be relevant.
A closed throttle position switch and wide open throttle position switch are built into the throttle position sensor unit. The wide open throttle position switch is used only for A/T control. When the throttle valve is in the closed position, the closed throttle position switch sends a voltage signal to open or close the EVAP canister purge volume control solenoid valve when the throttle position sensor is malfunctioning.