Fuel Tank
The fuel tank is molded of high-density polyethylene and incorporates two valves which operate during the refueling process to 1) control the flow of fuel vapor into the EVAP canister and 2) limit the flow of liquid fuel dispensed to canister. Both these valves are not serviceable, one is molded into the fuel tank shell (Fill Limit Vent Valve -FLVV) and the other is part of the fuel pump module (grade vent valve).
^ Fill Limit Vent Valve (FLVV) - Located on the top, rear surface of the fuel tank, next to the fuel pump module. This is a buoyant float type valve which controls the flow of fuel vapor into the EVAP canister during refueling.
^ Grade Vent Valve - Located at the upper end of fuel pump module on the fuel line that routes fuel vapor. This valve's primary function is prevent liquid fuel from leaving the fuel tank if 1) the vehicle is operated or parked on an incline or 2) the vehicle is involved in a roll-over accident.