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