Possible Causes

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.

Malfunction is detected when canister purge flow is detected when EVAP-CPVCSV is closed. Possible causes are:

Defective EVAP Control System Pressure Sensor (EVAP-CSPS).
EVAP-CPVCSV stuck open.
Defective EVAP Canister Vent Control Valve (EVAP-CVCV).
Defective EVAP canister.
EVAP system hoses misrouted or plugged.