Abstract: A diagnosis device is intended for an internal combustion engine including a supercharger, a blow-by gas passage that communicates between a portion of an intake passage and a crankcase, a PCV pressure sensor that detects a PCV pressure in the blow-by gas passage, and a crankshaft. The device executes specifying a specific period for which the amount of fluctuations in the intake air amount per unit time is a prescribed value or more on condition that the intake air amount is a determination air amount or more, calculating the amount of fluctuations in the PCV pressure during the specific period, and determining, based on the amount of fluctuations in the PCV pressure, the presence of an abnormality in the blow-by gas passage. The device sets the determination air amount to a smaller value when the rotational speed of the crankshaft is high than when the rotational speed is low.

Abstract: Apparatuses, systems and methods are disclosed including an internal combustion engine. The internal combustion engine can include an engine block defining a combustion chamber and a crankcase in fluid communication with the combustion chamber. The internal combustion engine can include an auxiliary device in fluid communication with the crankcase of the engine block. The auxiliary device is driven by the internal combustion engine to supply air to the crankcase of the engine block at a desired pressure range and a desired mass flow rate range to ventilate the crankcase.

Abstract: A fuel delivery system for an internal combustion engine system is described herein. The fuel delivery system uses one or more bidirectional purge components to provide for bidirectional purging of a fuel from at least a portion of the fuel delivery system. The bidirectional purge components provide for a fuel delivered using the fuel delivery system to be purged into the directional purge component in more than one fluid flow direction. When a differential pressure is applied across the bidirectional purge component, the fuel is purged into an inlet and an outlet of the bidirectional purge component, leaving the component through a purge outlet and into a tank. The differential pressure can be generated using a pressured fluid such as nitrogen or a pump downstream of the purge outlet.

Abstract: A leakage detector for a fuel vapor treatment device includes a fuel vapor treatment device that maintains the interior of a treatment system of the fuel vapor treatment device in a sealed state. In addition, the leakage detector includes; a closing valve and shutoff valve that can shut off fluid communication between the fuel tank and the canister to section the interior of the treatment system into a first region including the fuel tank and a second region including the canister. Further, the leakage detector includes an aspirator that applies a negative pressure to the second region.

Abstract: Methods and systems are provided for pinpointing a restriction in a vehicle evaporative emissions system which may adversely impact refueling and/or fuel vapor canister purging operations. In one example a method comprises conducting a diagnostic to identify a location of a restriction based on a rise time at which a pressure in a fuel system of a vehicle rises to a threshold pressure during a refueling event where fuel is added to the fuel system. In this way, a location of the restriction may be identified so as to enable appropriate mitigating action to be taken.

Abstract: Disclosed is a method for monitoring pressure, for a vessel assembly including a sealed vessel capable of holding a liquid, a filter capable of capturing vapors from the liquid, a pipe connecting the vessel to the filter, and an isolation valve arranged to selectively shut off the pipe, including a detection of the boiling of the liquid contained in the vessel.

Abstract: An inspection apparatus includes a pressure sensor, a reference orifice, a pump, and a switching valve. The reference orifice is disposed in a first communication passage communicating a pressure passage receiving the pressure sensor, with a tank passage communicating with a fuel tank. The pump depressurizing or pressurizing the pressure passage includes an intake port and a discharge port, and one of which communicates with an atmospheric passage communicating with the atmosphere and the other one communicates with the pressure passage. The switching valve and switches between a state shutting off a communication of a second communication passage that leads to the pressure passage and passages other than the pressure passage and communicating the atmospheric passage with the tank passage and a state shutting off a communication of the atmospheric passage and passages other than the pump and the atmosphere and communicating the second communication passage with the tank passage.

Abstract: Methods and systems are provided for regulating the flow of fuel vapor in an evaporative emissions system. In one example, a method may include re-routing fuel tank vapors responsive to an indication of a leaky canister purge valve such that fuel tank vapors may be efficiently adsorbed by a fuel vapor canister during engine-off conditions, rather than bypassing the fuel vapor canister and being released to the atmosphere. In this way, evaporative emissions may be prevented during the duration of time following an indication of a leaky canister purge valve and servicing the vehicle.

Abstract: A method, comprising generating a water-in-fuel indication responsive to a water-in-fuel content increasing more than a threshold amount within a threshold time of a refueling event is presented.

Abstract: A method for purging a fuel tank includes providing a three-way valve connected to the fuel tank via a first purging line, connected to a second purging line opening into a suction duct and connected to a third purging line opening into an adsorption container. A first path can be released in the three-way valve, based on the pressure inside the fuel tank exceeding a first predetermined opening pressure inside the fuel tank and the engine being in operation, such that the fuel vapours are caused to be purge out of the fuel tank into the suction duct. A second path can also be released in the three-way valve, based on the pressure inside the fuel tank exceeding a second predetermined opening pressure inside the fuel tank and the engine being not in operation, such that the fuel vapours are caused to be purged out of the fuel tank into the adsorption container.

Abstract: When fuel tank internal pressure is at a first predetermined pressure P1 or above over a first predetermined time length t1, a fuel tank shutoff valve is opened and a vapor solenoid valve is closed to make piping internal pressure equal to the fuel tank internal pressure. Then, a purge control valve is opened to emit fuel evaporative gas from the fuel tank into an intake passage. When the fuel tank internal pressure is continuously at a second predetermined pressure P2 or below over the first predetermined time length t1, the fuel tank shutoff valve is closed, and when accumulated volume in high-pressure purge finishing phase reaches a second predetermined volume iv2 or above, the vapor solenoid valve is opened. When the accumulated volume in high-pressure purge finishing phase reaches a first predetermined volume iv1 or above, the purge control valve is opened and the engine is stopped.

Abstract: A hybrid vehicle having a controller controls output torque of an engine and output torque of a generator motor so as to apply requested torque to a drive shaft. The controller performs engine intermittent operation to stop operation of the engine when a given engine operation stop condition is satisfied, and start the engine when a given engine start condition is satisfied. The controller makes an in-cylinder injection valve abnormality determination while causing a total amount of fuel to be injected from an in-cylinder injection valve, and makes a port injection valve abnormality determination while causing the total amount of fuel to be injected from a port injection valve. If at least one of abnormality determinations concerning the in-cylinder injection valve and the port injection valve has not been made, the engine is operated so that the load of the engine falls within a predetermined range.

Abstract: An evaporated fuel treatment device is provided to treat evaporated fuel by using a fuel supply cap with a small size while the flowout of fuel can also be suitably prevented. The evaporated fuel treatment device includes a positive pressure adjusting valve which opens when an inner pressure of a fuel tank becomes a predetermined pressure or more, and a spherical rollover valve which closes the positive pressure adjusting valve when the fuel tank is inclined at an angle equal to or larger than a predetermined angle. The positive pressure adjusting valve and the spherical rollover valve are mounted on one cylindrical portion formed on a fuel supply cap.

Abstract: A gas mixer for mixing a first gas and a second gas, including a gas housing, a Venturi tube, a flow body for the first gas arranged in the Venturi tube to form a mixing gap, an inflow tube connected to the Venturi tube, to an inflow opening to the Venturi tube for the second gas, and an actuating element for varying the inflow cross section of the inflow opening. The actuating element has a first and a second actuating part which restrict the inflow cross section. The first actuating part is a first gas housing part and the second actuating part is a second gas housing part. At least one of the gas housing parts forms part of the Venturi tube and/or of the inflow tube At least one of the gas housing parts can be moved with respect to another and has a rotor of a linear motor.

Abstract: A fuel vapor recovery system has a fuel tank, an adsorbent canister, a separator capable of separating fuel vapor from air, and a negative pressure supplier applying negative pressure to the adsorbent canister in order to remove the fuel vapor from the adsorbent canister. The separator has a housing and a separation membrane. The separation membrane divides an inner space of the housing into a receiving chamber and a permeation chamber and is configured to allow the fuel vapor to pass therethrough. The separator is connected with the fuel tank such that the fuel tank is fluidly connected with the receiving chamber. The negative pressure supplier is fluidly connected with the adsorbent canister via the permeation chamber. When the negative pressure supplier applies negative pressure to the adsorbent canister, purge gas flows from the adsorbent canister into the fuel tank via the permeation chamber.

Abstract: A venting system for a fuel tank includes a sorption filter for temporarily storing fuel evaporating from the fuel tank and a delivery device arranged between the sorption filter and an air supply system of an internal combustion engine in a fluid-conducting manner. The internal combustion engine is a turbocharged engine with a turbocharger unit and a throttling device in the air supply system. The sorption filter is connected to the air supply system in a fluid-conducting manner by a first line at a first inlet point arranged upstream of the turbocharger unit and by a second line at a second inlet point arranged downstream of the throttling device. A tank venting valve is arranged in the second line, and the first line branches off from the second line upstream of the tank venting valve in the flow direction towards the second inlet point.

Abstract: An isolation valve has an electrically-actuated solenoid valve, at least one port having a port extension, and a sensor assembly coupled to the port extension. The sensor assembly includes a printed circuit board, an integrated circuit disposed on the circuit board, and at least one pressure sensor coupled to the port extension to measure a vapor pressure in the port extension. In one embodiment, a single sensor assembly can monitor pressure at two or more ports. By integrating the sensor assembly into the isolation valve, the valve has a compact assembly that is easy to install in a vapor control system.

Abstract: 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.

Abstract: A vehicle includes an engine, a sealed fuel system having a fuel tank, a canister for storing fuel vapor, a vapor circuit external to the fuel tank, and a control valve. The vapor circuit includes an absolute pressure sensor and a switching valve connecting the fuel tank to the control valve. A controller evaluates or diagnoses a vapor purge function of the sealed fuel system using vacuum measurements from the absolute pressure sensor, executing or diagnosing only when the engine is running, purge is enabled, and the pump is off. The controller diagnoses the vapor purge function by comparing the vacuum measurements to a threshold vacuum. An apparatus includes the vapor circuit and controller. A method for diagnosing the vapor purge function includes actuating the switching valve, measuring a vacuum in the system using the absolute pressure sensor, and comparing the measured vacuum to a threshold vacuum.

Abstract: The invention relates to a method for regulating a fuel tank venting valve of a motor vehicle during leak testing of a fuel tank venting system where the fuel tank venting valve is arranged in a recovery line that connects a retention vessel to catch fuel vapors from a fuel tank to an inlet manifold of an operating internal combustion engine, comprising sealing the tank venting system from the atmosphere outside the motor vehicle, opening the fuel tank venting valve to expose the fuel tank and the tank venting system to a relative negative pressure present in the inlet manifold of the operating internal combustion engine and regulating the degree of opening of the tank venting valve based upon the external pressure, pA.

Abstract: According to the present teaching, a fuel vapor processing apparatus includes a fuel tank, a canister capable of adsorbing fuel vapor produced in the fuel tank, a fuel pump disposed within the fuel tank, a fuel recovery device configured to recover the fuel vapor from the canister into the fuel tank, and a control device configured to stop recovery of the fuel vapor by the fuel recovery device based on at least one of parameters representing the amount of the fuel vapor remaining within the canister.

Abstract: 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.

Abstract: According to the present teaching, a fuel vapor processing apparatus includes a fuel tank, a canister capable of adsorbing fuel vapor produced in the fuel tank, a fuel pump disposed within the fuel tank, a fuel recovery device configured to recover the fuel vapor from the canister into the fuel tank, and a control device configured to stop recovery of the fuel vapor by the fuel recovery device based on at least one of parameters representing the amount of the fuel vapor remaining within the canister.

Abstract: A evaporative emission control system includes a fuel tank, canister communicating with the fuel tank, air intake structure directing air to an internal combustion engine, a purge valve connected between the canister and the air intake structure, a vent valve associated with a source of ambient air, mixing structure associated with vent valve to selectively receive the ambient air that passes through the vent valve, a feed line connected between an exhaust flow path associated with the engine and the mixing structure, an output air flow from the mixing structure being received by the canister, and an exhaust valve in the feed line for controlling pressurized exhaust air flow, from the exhaust flow path, to the mixing structure. The exhaust air flow is mixed with the ambient air in the mixing structure with the output air flow therefrom purging the canister of hydrocarbons to be consumed by the engine.

Abstract: A canister for vehicles provided with an activated carbon to absorb an evaporation gas evaporated from a fuel tank, and releasing the absorbed evaporation gas to an engine, may include a housing to receive the activated carbon; an evaporation gas supply passage formed to the housing and fluid-connected to the fuel tank; an air passage formed to the housing and selectively receiving an air from the exterior of the housing; and a purge passage formed to the housing and fluid-connected to a purge line to supply the evaporation gas to the engine according to a flow of the received air, wherein the purge passage is provided with a first purge passage formed to the housing and directly fluid-connecting the housing to the purge line and a second purge passage formed to the housing and having an end portion positioned inside the first purge passage or the purge line.

Abstract: An internal combustion engine control apparatus includes: a purge control unit causing fuel evaporative emission to be introduced into an intake passage to attain a purge flow rate based on a pressure in the intake passage; a fuel cut return rich control unit setting a rich target air-fuel ratio when returning from fuel cut, and feedback-controlling a fuel supply rate on the basis of the target air-fuel ratio, purge flow rate and intake air flow rate to attain the target air-fuel ratio; a fuel increase upper limit setting unit setting an allowable upper limit for an increase in fuel supply rate in fuel cut return rich control; and an actual air-fuel ratio control unit controlling an actual air-fuel ratio to a richer side when the fuel supply rate in the fuel cut return rich control has reached the allowable upper limit and the actual air-fuel ratio is lean.

Abstract: 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.

Abstract: Methods and systems are provided for operating a fuel vapor recovery system having a fuel tank isolation valve coupled between a fuel tank and a canister. Fuel vapors are purged from the fuel tank to a canister buffer over a plurality of purge pulses. The pulses are adjusted based on the buffer capacity, a purge flow rate, and a fuel tank pressure to improve control of canister loading and reduce air-to-fuel ratio disturbances.

Abstract: An evaporative emission control system for a fuel tank of a vehicle includes a diurnal control module coupled to a vapor exhaust line running between the fuel tank and an activated carbon canister. A purge line is coupled to the canister and is open to atmospheric pressure. The purge line includes a breathing loss accumulator that collects fuel vapors expelled from the canister during diurnal thermal expansion. The diurnal control module closes fluid communication between the fuel tank and the canister when the fuel tank is not being refueled to maintain the fuel tank in a pressurized condition and the canister in a non-pressurized condition.

Abstract: A method for combusting a vapor of a fuel accumulated in an adsorbent canister in a vehicle, the vehicle having an engine and a fuel tank coupled to the adsorbent canister. The method comprises, during a first operating condition including a higher availability of compressed air, metering the compressed air from a first air source, and flowing the metered, compressed air through the adsorbent canister along a first flow path. The method further comprises, during a second operating condition including a lower availability of compressed air, flowing air from a second air source through the adsorbent canister, and, during the first and second operating conditions, venting the fuel tank to an intake of the engine and flowing effluent enriched in the vapor from the adsorbent canister to the intake of the engine.

Abstract: A vehicle fuel emissions system includes a fuel tank, a tank pressure sensor indicating a pressure differential between the tank and a port communicating with the atmosphere, a pump for selectively producing vacuum in the tank, and a passage connecting the pump and a pressure sensor air reference port external to the system.

Abstract: A fuel vapor processing apparatus includes a purge air supply device including separation device that can separate gas, which is introduced from within a fuel tank, into a fuel component and an air component. The air component is supplied into a canister for purging the canister.

Abstract: An evaporated fuel treatment device is provided to treat evaporated fuel by using a fuel supply cap with a small size while the flowout of fuel can also be suitably prevented. The evaporated fuel treatment device includes a positive pressure adjusting valve which opens when an inner pressure of a fuel tank becomes a predetermined pressure or more, and a spherical rollover valve which closes the positive pressure adjusting valve when the fuel tank is inclined at an angle equal to or larger than a predetermined angle. The positive pressure adjusting valve and the spherical rollover valve are mounted on one cylindrical portion formed on a fuel supply cap.

Abstract: An evaporative fuel treatment apparatus for a vehicle is provided with a reverse flow preventing valve provided in a fuel supply pipe, a positioning plate provided on the fuel supply pipe, a pressing plate mounted slidably on the fuel supply pipe between the positioning plate the reverse flow preventing valve, a seal member clamped between the positioning plate and the pressing plate, and a stopper. When the fuel supply is started, the reverse flow preventing valve is configured to be set opened so as to form a liquid trap between the reverse flow preventing valve and the pressing plate. When the liquid surface reaches the pressing plate, the fuel pushes the pressing plate upward and the seal member is collapsed in the vertical direction so that the seal member protrudes toward the fuel supply gun insertion holes and makes tight contact with the fuel supply gun to seal a gap.

Abstract: A method for combusting a vapor of a fuel accumulated in an adsorbent canister in a vehicle, the vehicle having an engine and a fuel tank coupled to the adsorbent canister. The method comprises, during a first operating condition including a higher availability of compressed air, metering the compressed air from a first air source, and flowing the metered, compressed air through the adsorbent canister along a first flow path. The method further comprises, during a second operating condition including a lower availability of compressed air, flowing air from a second air source through the adsorbent canister, and, during the first and second operating conditions, venting the fuel tank to an intake of the engine and flowing effluent enriched in the vapor from the adsorbent canister to the intake of the engine.

Abstract: A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.

Abstract: A canister for a vehicle, and more particularly, a canister with dual air flow paths is configured to divide an inner space of an air entrance of the canister into two spaces and allow air to flow in from an outdoor atmosphere through one space between two spaces in a purging operation and discharge fuel evaporation gas to the outdoor atmosphere through the other space when the fuel evaporation gas is discharged in order to prevent pressure in a fuel tank from being raise

Abstract: A fuel vapor recovery system has a fuel tank, an adsorbent canister, a separator capable of separating fuel vapor from air, and a negative pressure supplier applying negative pressure to the adsorbent canister in order to remove the fuel vapor from the adsorbent canister. The separator has a housing and a separation membrane. The separation membrane divides an inner space of the housing into a receiving chamber and a permeation chamber and is configured to allow the fuel vapor to pass therethrough. The separator is connected with the fuel tank such that the fuel tank is fluidly connected with the receiving chamber. The negative pressure supplier is fluidly connected with the adsorbent canister via the permeation chamber. When the negative pressure supplier applies negative pressure to the adsorbent canister, purge gas flows from the adsorbent canister into the fuel tank via the permeation chamber.

Abstract: A method for combusting a vapor of a fuel accumulated in an adsorbent canister in a vehicle, the vehicle having an engine and a fuel tank coupled to the adsorbent canister. The method comprises, during a first operating condition including a higher availability of compressed air, metering the compressed air from a first air source, and flowing the metered, compressed air through the adsorbent canister along a first flow path. The method further comprises, during a second operating condition including a lower availability of compressed air, flowing air from a second air source through the adsorbent canister, and, during the first and second operating conditions, venting the fuel tank to an intake of the engine and flowing effluent enriched in the vapor from the adsorbent canister to the intake of the engine.

Abstract: A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.

Abstract: A vehicle includes an engine, a sealed fuel system having a fuel tank, a canister for storing fuel vapor, a vapor circuit external to the fuel tank, and a control valve. The vapor circuit includes an absolute pressure sensor and a switching valve connecting the fuel tank to the control valve. A controller evaluates or diagnoses a vapor purge function of the sealed fuel system using vacuum measurements from the absolute pressure sensor, executing or diagnosing only when the engine is running, purge is enabled, and the pump is off. The controller diagnoses the vapor purge function by comparing the vacuum measurements to a threshold vacuum. An apparatus includes the vapor circuit and controller. A method for diagnosing the vapor purge function includes actuating the switching valve, measuring a vacuum in the system using the absolute pressure sensor, and comparing the measured vacuum to a threshold vacuum.

Abstract: A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.

Abstract: Methods and systems are provided for operating a fuel vapor recovery system having a fuel tank isolation valve coupled between a fuel tank and a canister. Fuel vapors are purged from the fuel tank to a canister buffer over a plurality of purge pulses. The pulses are adjusted based on the buffer capacity, a purge flow rate, and a fuel tank pressure to improve control of canister loading and reduce air-to-fuel ratio disturbances.

Abstract: An evaporated fuel treating apparatus that realizes enhanced exertion of the treating capability of a canister for evaporated fuel and thus efficient treatment of evaporated fuel. Vapor piping for feeding an evaporated fuel from fuel tank to canister is provided with first close valve. The first close valve is capable of regulating the flow rate of transit evaporated fuel through regulation of the opening degree thereof. Accordingly, the evaporated fuel treating capability of the canister can be exerted higher than in the system in which the flow rate of evaporated fuel is not regulated.

Abstract: According to the present teaching, a fuel vapor processing apparatus includes a fuel tank, a canister capable of adsorbing fuel vapor produced in the fuel tank, a fuel pump disposed within the fuel tank, a fuel recovery device configured to recover the fuel vapor from the canister into the fuel tank, and a control device configured to stop recovery of the fuel vapor by the fuel recovery device based on at least one of parameters representing the amount of the fuel vapor remaining within the canister.

Abstract: A three-port valve includes a valve body including a first port, a second port, and a third port, the first port having a first valve orifice and the second port having a second valve orifice. The valve may also include a first valve closure member and a second valve closure member, the first and second valve closure members may be configured to selectively seal the first and second valve orifices, respectively. The valve may further include a solenoid including a first coil and a second coil, at least one of the first and second coils configured to actuate at least one of the first and second valve closure members when energized. Additionally, the valve may include an electrical connection configured to selectively and individually energize the first and second coils. The valve may be configured to operate in at least three different states of operation. For example, the three-port valve may have a first state (e.g.

Abstract: A vehicle fuel emissions system includes a fuel tank, a tank pressure sensor indicating a pressure differential between the tank and a port communicating with the atmosphere, a pump for selectively producing vacuum in the tank, and a passage connecting the pump and a pressure sensor air reference port external to the system.

Abstract: A leakage diagnosis device can determine whether or not leakage occurs from a fuel vapor processing apparatus by comparing a diagnosis criterion, such as a reference pressure set for diagnosing leakage, with an internal pressure of a process system of the fuel vapor processing apparatus during application of a negative or positive pressure to the process system. The diagnosis criterion has a device that can correct the diagnosis criterion based on a fuel vapor pressure within the process system.

Abstract: A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.

Abstract: A method of controlling an evaporative emissions system of a vehicle includes determining that a refueling event has been requested by a vehicle occupant, detecting a pressure inside a fuel tank, and impeding opening of a fuel tank inlet if the pressure is above a limit value. After the refueling event, an open/closed status of a fuel inlet access door is monitored, a fuel level inside a fuel tank is monitored, and a vehicle engine an operating condition is monitored. Pressure buildup within the fuel tank is disabled if a) the open/closed status has not changed from closed to open, and b) the fuel level has increased, and c) the vehicle engine is operating. An operator alert may be generated, and/or a fault code may be set in a vehicle diagnostic system.