Fill Limiter Vent Valve
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
The cross sectional view of the Fill Limiter Vent Valve (FLVV) shows the path of fuel vapors leaving the fuel tank by passing thorough the valve to the EVAP canister. See Fig 1 . When the fuel filler cap is removed during refueling, the atmosphere chamber fills with atmospheric pressure that has entered through the port from the fuel filler pipe. The pressure in the atmosphere chamber opens the port to the EVAP canister by closing the vent control valve. Refueling causes the internal pressure in the fuel tank to increase, pushing fuel vapors into the FLVV and out to the EVAP canister. When the fuel tank is full, the tank vapor control valve closes, sealing off the port to the EVAP canister.