Controlling the closing force of a canister purge valve prior to executing leak diagnostic
AssigneeFord Global Technologies, LLC
InventorsMark W. Peters, Matthew Werner, Scott A. Bohr, Aed M. Dudar
Life of this patent
Estimating the term…
Abstract
A method for a vehicle having a fuel vapor canister coupled between a fuel tank and an engine intake manifold via an electronically controlled purge valve, comprises initiating a vapor leak test under predetermined conditions and in response to the initiation, fully opening the purge valve from a closed position to a fully open position for a predetermined time, and then fully closing the purge valve after the predetermined time and commencing the leak test.
Claims16
A method for a vehicle having a fuel vapor canister coupled between a fuel tank and an engine intake manifold via an electronically controlled purge valve, comprising:
- initiating a vapor leak test under predetermined conditions;
- and
- in response to said initiation, opening said purge valve from a closed position to an open position for a predetermined time;
- opening and closing a vent valve coupled to said fuel vapor canister during said predetermined time;
- closing said purge valve after said predetermined time;
- fully opening said purge valve for a second predetermined time;
- and then fully closing said purge valve before commencing said leak test.
A method for a vehicle system having a carbon canister coupled between a fuel tank and an engine intake manifold via an electronically controlled purge valve, comprising:
- conducting a fuel vapor leak test based on predetermined engine conditions;
- before commencing said leak test, opening said purge valve for a preselected time;
- then closing said purge valve for a first predetermined time;
- then fully opening said purge valve for a second predetermined time;
- and then fully closing said purge valve and commencing said leak test.
A method for a vehicle system having a carbon canister coupled between a fuel tank and an engine intake manifold via an electronically controlled purge valve, comprising:
- initiating a fuel vapor purge based upon preselected engine conditions by opening said purge valve and inducting fuel vapors from said canister into said engine intake manifold;
- stopping said fuel vapor purge by closing said purge valve based on a determination that fuel vapors absorbed in said canister are less than a threshold;
- initiating a fuel vapor leak test when predetermined conditions are met;
- in response to said initiation, fully opening said purge valve from a closed position to a fully open position for a predetermined time;
- and then fully closing said purge valve;
- and opening said purge valve for a preselected time before commencing said leak test.
Dependencies are inferred from the claim text.