Patent ID: 11879408
Assignee: FORD GLOBAL TECHNOLOGIES, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 7:
8. A method for an engine in a vehicle, comprising:
upon receiving a request for refueling,
during a first condition, actuating a fuel tank isolation valve (FTIV) to a first position to depressurize a fuel tank,
during a second condition, actuating the FTIV to a second position to depressurize the fuel tank, and
during depressurization, indicating degradation of the FTIV based on a rate of pressure decay in the fuel tank,
wherein the first condition includes a lower than threshold load in a fuel vapor canister, and wherein actuating the FTIV to the first position establishes fluidic communication between the fuel tank and a load port of the fuel vapor canister,
wherein the second condition includes a higher than threshold load in the fuel vapor canister, and wherein actuating the FTIV to the second position establishes fluidic communication between the fuel tank and a depressurization port of the fuel vapor canister, the load port positioned on a proximal end of the fuel vapor canister with a purge port, and the depressurization port positioned on a distal end of the fuel vapor canister with a vent port, and
in response to each of the rate of pressure decay in the fuel tank during depressurization being lower than a decay threshold rate and one or more premature shut-offs during refueling, indicating degradation of a cross over valve (COV) of an evaporative leak check module (ELCM) housed in a vent line.