DTC P2401, P2402: Evaporative Emission Leak Detection Pump Stuck OFF; Evaporative Emission Leak Detection Pump Stuck ON: Description
WARNING: This page is about a different car, the 2006 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The circuit description can be found in the Evaporative Emission (EVAP) system (see EVAP System (2005/05-2006/01) ).