Fuel Limit Vent Valve
WARNING: This page is about a different car, the 2018 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.
The Fuel Limit Vent Valve (FLVV) allows the fuel tank to be filled to its maximum. The air within the fuel tank expelling through an internal breather which is connected to a stub port, passing through the fuel tank carcass. A combined fuel vapor and breather external hose connect to this port. A pipe connection splits the combined hose to independently connect pipes to the fuel filler neck and the Evaporative Emission (EVAP) canister.
For additional information, refer to: Evaporative Emissions .