Patent application number | Description | Published |
20110132325 | SYSTEM AND METHOD FOR REDUCING PARTICULATE MATTER PRODUCED BY AN ENGINE - A method for reducing particulate matter emitted by an engine is disclosed. In one example, the start of fuel injection timing is adjusted in response to a change in engine operating conditions. In particular, start of injection timing may be advanced and then retarded to promote fuel vaporization. | 06-09-2011 |
20120227580 | Fuel System Diagnostics - An emissions control system is provided that comprises a fuel tank, a hydrocarbon filter element, and a three-way valve coupled between the hydrocarbon filter element and the atmosphere. The three-way valve is comprised of three ports, a purge port, a reference port, and a sealed port, and enables identification of degradation of the emissions control system. The arrangement of the ports on the valve enables a simplified testing method that reduces background errors caused by transitioning between various operating positions. | 09-13-2012 |
20130032127 | METHOD AND SYSTEM FOR FUEL VAPOR CONTROL - Methods and systems are provided for operating an engine to generate vacuum for a subsequent leak detection routine. During a selected key-off condition, a starter motor is operated to spin the engine unfueled and generate intake vacuum for the leak detection. Fuel vapors drawn during the spinning are stored in an auxiliary canister that is purged along with a main canister during purging conditions. | 02-07-2013 |
20130112176 | METHOD AND SYSTEM FOR FUEL VAPOR CONTROL - Methods and systems are provided for generating sufficient vacuum to enable a leak detection routine. While a fuel tank pressure is within mechanical limits, fuel vapors are purged from a canister to an engine with an isolation valve open to generate a desired level of vacuum in the fuel tank. Thereafter, the fuel tank is isolated and leak detection is performed concurrent to the purging. | 05-09-2013 |
20130253799 | FUEL SYSTEM DIAGNOSTICS - Methods and systems are provided for detecting a fuel system leak. One or more of a boost pressure from a compressor and vacuum from an intake manifold is sequentially applied on a fuel tank. A leak is detected based on a subsequent change in fuel tank pressure. | 09-26-2013 |
20130269660 | METHOD FOR PURGING FUEL VAPORS TO AN ENGINE - A method for improving purging of fuel vapors from a fuel vapor storage canister to an engine is presented. In one example, the method adjusts engine operation to provide sonic flow between a canister and the engine. In this way, it may be possible to lower an amount of fuel vapors stored in a canister while the engine continues to operate efficiently. | 10-17-2013 |
20130298879 | EVAPORATIVE EMISSION CONTROL - A method for operating a fuel system is disclosed. The method includes sequentially purging fuel vapors from each of a plurality of regions of a canister. Purging a region includes opening an air inlet valve associated with that region and maintaining air inlet valves associated with each other region closed to direct fuel vapors to at least one purge outlet. | 11-14-2013 |
20140026866 | METHOD AND SYSTEM FOR FUEL SYSTEM CONTROL - Methods and systems are provided for controlling a fuel system in a hybrid vehicle. Before canister purging is stopped by closing a purge valve, a canister vent valve is closed to hold fuel tank vacuum. Then, during a subsequent canister purge, the purge valve is opened before opening the vent valve, allowing canister purge to initiate under fuel tank vacuum conditions. | 01-30-2014 |
20140033802 | FUEL SYSTEM DIAGNOSTICS - An emissions control system is provided that comprises a fuel tank, a hydrocarbon filter element, and a three-way valve coupled between the hydrocarbon filter element and the atmosphere. The three-way valve is comprised of three ports, a purge port, a reference port, and a sealed port, and enables identification of degradation of the emissions control system. The arrangement of the ports on the valve enables a simplified testing method that reduces background errors caused by transitioning between various operating positions. | 02-06-2014 |
20140069394 | FUEL SYSTEM DIAGNOSTICS - Methods and system are provided for identifying unintended closing (or corking) of a mechanical valve coupled to a fuel tank. If tank vent valve corking is identified during a leak test, fuel tank pressure data collected during the leak test is disregarded and not used to determine a fuel system leak. Instead, a fuel system leak test is repeated to improve reliability of test results. | 03-13-2014 |
20140114550 | VEHICLE METHOD FOR BAROMETRIC PRESSURE IDENTIFICATION - A vehicle method for barometric pressure identification, including adjusting engine operation responsive to barometric pressure, the barometric pressure based on a pressure change at a sector of the fuel system when the sector is sealed with the vehicle travelling. The method may utilize a pressure change at the sealed sector of the fuel system, such as a sealed fuel tank, to identify barometric pressure, even with the engine off for extended durations of vehicle travel. As such, in a hybrid-vehicle application, including during hill descents in which the engine is maintained off, barometric pressure can still be updated. | 04-24-2014 |
20140130781 | FUEL SYSTEM DIAGNOSTICS - Methods and system are provided for distinguishing fuel tank vacuum generation due to canister purge valve degradation from vacuum generation due to canister vent valve degradation. A fuel tank vacuum level is monitored after sealing the fuel tank from the atmosphere following an engine pull-down. If there is an ensuing change in fuel tank vacuum, canister purge valve degradation is determined, else, canister vent valve degradation is determined. | 05-15-2014 |
20140209069 | CONTROLLING THE CLOSING FORCE OF A CANISTER PURGE VALVE PRIOR TO EXECUTING LEAK DIAGNOSTIC - 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 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 after said predetermined time and commencing said leak test. | 07-31-2014 |
20140216421 | PARTIALLY SEALED FUEL VAPOR PURGE SYSTEM - Systems and methods for operating an engine with a fuel vapor recovery system are disclosed. In one example approach, a method comprises, during a diurnal condition, providing a first amount of venting to a fuel vapor canister, and during a purge condition, providing a second amount of venting to the fuel vapor canister, where the second amount is greater than the first amount. | 08-07-2014 |
20140230795 | FUEL SYSTEM CONTROL - Methods are provided for reliving excess vacuum from a fuel tank. In response to elevated fuel tank vacuum levels, a canister purge valve is opened to dissipate the vacuum to an engine intake manifold while the engine is not combusting. Alternatively, the purge valve is opened to dissipate the excess vacuum to the intake manifold while the engine is combusting during conditions when the likelihood of air-fuel ratio errors are lower or when any incurred errors are better tolerated. | 08-21-2014 |
20140251284 | MULTI-PATH PURGE EJECTOR SYSTEM - Systems and methods for a multi-path purging ejector are disclosed. In one example approach, a multi-path purge system for an engine comprises an ejector including a restriction, first and second inlets, and an outlet, and a shut-off valve hard-mounted to an intake of the engine and coupled to the outlet. | 09-11-2014 |
20140251285 | INTAKE AIR OXYGEN COMPENSATION FOR EGR - A method may comprise correcting an intake oxygen concentration based on fuel canister vapor purge only during boosted conditions, and adjusting exhaust gas recirculation responsive to the intake oxygen concentration. | 09-11-2014 |
20140257668 | ENGINE-OFF REFUELING DETECTION METHOD - A method for an engine fuel system comprises, during an engine-off condition, indicating a refueling event based on a rate of change in fuel tank pressure, and aborting a diagnostic leak detection test based on the refueling event indication. Indicating a refueling event further comprises indicating a refueling event based on the rate of change in fuel tank pressure being greater than a first threshold when the canister vent valve is open, and greater than a second threshold when the canister vent valve is closed, the first threshold being less than the second threshold. | 09-11-2014 |
20140260549 | FUEL SYSTEM LEAK DETECTION USING PASSIVE VALVES - Methods and systems for fuel system leak detection using passive canister vent valves are disclosed. In one example approach, a method comprises generating engine off vacuum or pressure in a fuel system for leak diagnostics, where the pressure and vacuum are held via first and second mechanical relief valves positioned in parallel with one another and without a valve holding current. | 09-18-2014 |
20140311461 | CANISTER PURGE VALVE SELF-CLEANING CYCLE - A method for a fuel system coupled to an engine comprising: under vacuum conditions, opening the fuel vapor canister purge valve, and generating pressure pulsations in a conduit coupled to the fuel vapor canister purge valve by opening and closing a fuel vapor canister vent valve one or more times while maintaining the fuel vapor canister purge valve open. In this way, contaminants and/or debris that may prevent the canister purge valve from closing completely may be dislodged and evacuated to the intake manifold. | 10-23-2014 |
20140316638 | HYBRID VEHICLE FUEL SYSTEM LEAK DETECTION - Methods and systems for fuel system leak detection in a hybrid electric vehicle using a fuel reservoir are disclosed. In one example approach, a method comprises, during an engine off condition, delivering fuel from a fuel tank into a reservoir while the fuel tank is vented to atmosphere, and sealing the fuel tank from atmosphere and indicating a leak based on pressure in the fuel tank. | 10-23-2014 |
20140318506 | AIR INTAKE SYSTEM HYDROCARBON TRAP PURGING - Methods and systems for passively purging a hydrocarbon trap in an engine intake in a vehicle are disclosed. In one example approach, a method comprises, in response to an ambient temperature decrease during an engine off condition while a fuel tank is sealed from atmosphere, delivering fuel stored in a hydrocarbon trap in an intake of the engine to a fuel vapor canister coupled to the fuel tank in an emission control system. | 10-30-2014 |
20140336873 | INTERNAL ORIFICE CHARACTERIZATION IN LEAK CHECK MODULE - Systems and methods for internal orifice characterization in an evaporative leak check module are disclosed. In one example approach, a method comprises operating a pump to draw air from an emission control system through an orifice to obtain a reference pressure, and indicating a leak in response to pressure in the emission control system remaining above a threshold pressure while operating the pump to decrease pressure in the emission control system, where the threshold pressure is based on a coded indication and the reference pressure. | 11-13-2014 |
20140345575 | CANISTER PURGING FOR PLUG-IN HYDRID ELECTRIC VEHICLES - A method for desorbing fuel vapors from a canister of a vehicle having an internal combustion engine and a fuel tank includes detecting the temperature within the interior of the fuel tank using a temperature sensor positioned within the fuel tank. The canister is in fluid communication with the fuel tank and an intake manifold of the engine of the vehicle. A vapor bypass valve is positioned along a flow line between the fuel tank and the canister. The vapor bypass valve is opened if the temperature inside the fuel tank falls below a pre-determined value. The low pressure region created within the fuel tank due to fall in temperature is utilized to route ambient air along with the fuel-vapors contained within the canister, towards the fuel tank, through the opened vapor bypass valve. | 11-27-2014 |
20150020779 | FUEL TANK PRESSURE RELIEF VALVE CLEANING - Methods and systems for cleaning a pressure relieve valve for a fuel tank are disclosed. In one example approach a method for cleaning a pressure relief valve that is normally activated at a preset negative pressure in a fuel system comprises, during a test cycle, reducing fuel system pressure to a predetermined pressure which is higher than the preset pressure, and measuring pressure changes in the fuel system; and when not in the test cycle, periodically reducing the fuel system pressure to a third pressure which is less than said preset pressure. | 01-22-2015 |
20150068498 | SYSTEMS AND METHODS FOR A TWO-VALVE NON-INTEGRATED REFUELING CANISTER ONLY SYSTEM - A system for a vehicle, comprising: a tank pressure control valve coupled in a first conduit between a fuel tank and a fuel vapor canister; a refueling valve coupled in a second, different, conduit between the fuel tank and the fuel vapor canister, the second conduit in parallel to the first conduit. In this way, two smaller, less complex valves may be utilized to control fuel tank vapor purging and fuel tank depressurization during refueling. This in turn may lower system cost and increase system functionality. | 03-12-2015 |
20150075501 | FUEL TANK PRESSURE SENSOR RATIONALITY TEST FOR A PHEV - A method for verifying the reliable operation of a fuel tank pressure transducer positioned within a fuel tank of a PHEV. The method detects the initiation of a refueling cycle, which leads to opening a system vent valve positioned between a carbon canister and a system vent, and opening a fuel tank isolation valve. A controller monitors fuel system pressure within the fuel tank and at the vent valve, and that device determines rates of change of the fuel system pressure within the fuel tank and at the outlet vent. Reliable operation of the fuel tank pressure transducer is indicated upon a determination that the rates of change of the fuel system pressure in the fuel tank and at the outlet vent are uniform within a predetermined range. | 03-19-2015 |
20150083087 | METHOD AND SYSTEM FOR FUEL VAPOR CONTROL - Methods and systems are provided for identifying leaks on each of a fuel tank and a canister side of a fuel system using a single leak check module. A position of a switching valve coupled in the vapor line of the fuel system is adjusted to selectively couple the leak check module to either the fuel tank or the canister. Leak is detected based on a change in pressure at a reference orifice of the leak check module following applying of vacuum from a vacuum pump. | 03-26-2015 |