Patent ID: 6276193
Filing Date: 2001-08-21
Classification: F02M

Abstract:
A method of detecting vapor leaks in a motor vehicle fuel tank vapor management system of the type having a vapor storage canister comprising:(a) disposing a valve in the air inlet of said canister and providing a fluid pressure responsive member in said valve and biasing said member to the open position with a predetermined force;(b) sensing fuel vapor temperature in said tank and remotely actuating said valve to the closed position when the tank temperature has decreased by a predetermined amount;(c) applying the tank pressure to said pressure responsive member and overcoming said predetermined force and holding said valve closed when said tank vapor pressure is below a certain sub-atmospheric vapor pressure and opening said valve with said predetermined force if said tank vapor pressure rises above said certain sub-atmospheric pressure.(d) detecting the position of said valve and thereby determining that said valve is open and leakage is present in said system; and,(e) providing a fault indication when said leakage is present.