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US 9,751,396 B2Granted
Fuel tank pressure sensor rationality for a hybrid vehicle during refueling
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for performing fuel tank pressure sensor rationality for a hybrid electric vehicle during refueling. In one example, a method may include indicating degradation of the fuel tank pressure sensor based on the pressure detected in the canister vent line when the canister vent line is restricted.
Claims20
A method for a fuel emissions system of a hybrid vehicle, comprising:
- during a refueling event when a fuel tank is being refueled and while a fuel tank level is increasing,
- maintaining a fuel vapor canister vent line restriction;
- and
- indicating degradation of a fuel tank pressure sensor based on a pressure in a canister vent line.
1 more element
A system for a hybrid-electric vehicle, comprising:
- a fuel tank isolation valve coupled in a conduit between a fuel tank and a fuel vapor canister;
- a fuel tank pressure sensor;
- an evaporative leak check module (ELCM) coupled in a conduit between the fuel vapor canister and atmosphere, the ELCM comprising a vacuum pump, an ELCM pressure sensor, and a change-over valve operable between a first position and a second position;
- and
- a controller configured with instructions stored in non-transitory memory that when executed cause the controller to:
- during refueling of the fuel tank, perform an evaporative leak check routine by:
- adjusting the change-over valve to the first position;
- and
- comparing fuel tank pressure sensor output and ELCM pressure sensor output and indicating degradation of the fuel tank pressure sensor when a rate of change of the fuel tank pressure sensor output is lower than a rate of change of the ELCM pressure sensor output by at least a threshold amount.
6 more elements
A method, comprising:
- responsive to a request to perform a fuel tank refuel, comparing fuel tank pressure to atmospheric pressure;
- when fuel tank pressure is not equal to atmospheric pressure, indicating degradation of a fuel tank pressure sensor based on a correlation between fuel tank pressure sensor output and canister vent line pressure during fuel tank depressurization prior to the fuel tank refuel;
- and
- when fuel tank pressure is substantially equal to atmospheric pressure, indicating degradation of the fuel tank pressure sensor based on a correlation between fuel tank pressure sensor output and canister vent line pressure during the fuel tank refuel and while a fuel tank level is increasing.
1 more element
Dependencies are inferred from the claim text.