EVAP Vent Solenoid
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP vent solenoid controls fresh airflow into the EVAP canister. The solenoid is normally open. The Powertrain Control Module (PCM) will command the solenoid closed during some EVAP tests, allowing the system to be tested for leaks.