Ford Global Technolgoies, LLC

David Allen Clemens

Aed M Dudar

Robert Roy Jentz

Michael Igor Kluzner

Douglas Raymond Martin

Kenneth James Miller

David Michael Bevan

Ann Irene DeZelia

Ann Irene Sipes

A method is provided for performing an evaporative leak diagnostic for a vehicle. A valve in a diagnostic module is commanded to a vent position. The valve connects a fuel system to atmosphere. A pump in the diagnostic module is operated to measure a reference pressure across an orifice in the diagnostic module to provide a threshold. The valve is commanded to a test position. The pump is operated to place the fuel system in a low pressure state. A series of pressures in the fuel system is measured. A diagnostic code is provided after comparing the series of pressures to the threshold.

System and method for performing evaporative leak diagnostics in a vehicle

A vehicle is provided with a fuel system, a controller, and a diagnostic module with an orifice, a pressure sensor, and a pump, the module connecting the fuel system to atmosphere. The controller measures a reference pressure across the orifice to provide a threshold, isolates the fuel system, and provides a code in response to comparing a series or measured pressures to the threshold. A method for performing an evaporative leak diagnostic is provided. A valve in a diagnostic module is commanded to a vent position. A pump is operated to measure a reference pressure across an orifice to provide a threshold. A valve is commanded to a test position. The pump is operated to place the fuel system in a low pressure state, and a series of pressures in the fuel system is measured. A diagnostic code is provided after comparing the series of pressures to the threshold.

A control scheme is disclosed for performing both an adaption routine and carbon canister purging. In adaption, parameters for estimating air-fuel ratio from flow sensors and actuators are adjusted against an air-fuel ratio under closed-loop control using an EGO sensor. The two processes cannot run simultaneously. In vehicles in which the engine is operating from the time of key on until key off, the adaption occurs shortly after starting and then periodically thereafter. In vehicles in which the engine is turned on and off frequently such as with HEVs, the adaption routine may be run every time the engine is turned on, which is more frequent than necessary and doesn't allow enough time for purging. According to the disclosed control scheme, the time since last adaption and time in adaption is saved when the engine is turned off so that the adaption routine is conducted only when needed.

Method to perform carbon canister purge and adaption of air-fuel ratio estimation parameters

A system and method for controlling the introduction of purge fuel vapor into a multi-cylinder internal combustion engine is provided. According to one aspect of the disclosure, a schedule for opening and closing an on-off, pulse-width-modulated, purge control valve is predetermined, and the purge control valve is opened and closed according to the predetermined schedule. According to one aspect of the disclosure, a predetermined schedule can include a repeating sequence of on-pulse frequencies.

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Canton, MI, United States of America

David Allen Clemens