Patent ID: 8551214

Claim:
A method controlling an emissions control system coupled to an internal combustion engine, the emissions control system including a vapor recovery line fluidically coupling a fuel tank to a hydrocarbon filter element, a vent line positioned between the hydrocarbon filter element and atmosphere, a valve having a first, second, and third connection port, the valve arranged within the vent line between the hydrocarbon filter element and a fresh air filter arranged on the atmosphere side of the vent line, the method comprising: during a first operating mode, routing vapors from the hydrocarbon filter element through the valve to the atmosphere via the first port with the valve in a first position; during a second operating mode, routing vapors from the hydrocarbon filter element through the valve to the atmosphere via the second port with the valve in a second position, the second port comprising a leak reference orifice; and during a third operating mode, storing vapors in the hydrocarbon filter element and the fuel tank, wherein the valve is fluidically coupled to the hydrocarbon filter element via the third port with the valve in a third position.