Abstract: 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.

Abstract: A method for detecting blockage within a recirculation tube of the evaporative emission control system of a PHEV measures the rise in interior temperature of a canister of the EVAP system, during the process of refueling, and notes an initial state of loading of the canister before refueling, indicative of the amount of hydrocarbons contained within the canister It is inferred that the recirculation tube is operative reliably if the rise in canister temperature is below a pre-determined temperature value.

Abstract: 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.

Abstract: Methods and systems for fuel system leak detection are disclosed. In one example approach, a method comprises, in response to a pressure change in a fuel tank less than a threshold for a duration during engine-off conditions while the tank is sealed off from atmosphere, indicating a leak condition, and in response to a pressure change in the tank greater than the threshold during engine-off conditions while the tank is sealed off from atmosphere, indicating a no-leak condition.

Abstract: System for detecting leakage within a canister purge valve of an evaporative emission control system. The system includes a power train control module connected to the canister purge valve, configured to command the canister purge valve between open and closed positions. In addition, the system includes a flow meter having an inlet and an outlet. The inlet is in fluid communication with ambient air surrounding the vehicle, and the outlet is in fluid communication with an inlet of the canister purge valve. The system further includes a control module operatively connected to the flow meter. The control module is programmed to analyze flow through the flow meter; compare the measured flow to predetermined flow data; and to indicate whether that flow exceeds a predetermined level.

Abstract: Methods and systems for fuel system leak detection are disclosed. In one example approach, a method comprises, during an engine-on condition, delivering fuel from a fuel tank to one or more cylinders of the engine while the fuel tank is sealed off from atmosphere, and indicating a leak based on pressure in the fuel tank. For example, a leak may be indicated in response to a pressure decrease in the fuel tank greater than an expected pressure decrease, where the expected pressure decrease is based on a fuel level in the fuel tank.

Abstract: 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.

Abstract: A distensible fuel tank included in a vehicle is provided. The distensible fuel tank includes a housing having an exterior surface and a lattice structure coupled to the exterior surface, the lattice structure including a plurality of intersecting wall members, at least two of the plurality of wall members having an unequal thickness.

Abstract: Methods and systems for purging a hydrocarbon trap in an engine intake in a vehicle are disclosed. In one example approach, a method comprises during an engine off condition, operating a pump in a purge line coupled to a fuel vapor canister in an emission control system to deliver fuel stored in a hydrocarbon trap in an intake of the engine to the fuel vapor canister.

Abstract: 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.

Abstract: A system for a vehicle is provided herein. The system includes a fuel vapor canister comprising a shell, a compression plate within the shell and an end cap. The end cap includes a double sided spring interface and a double sided shell sealing surface having double sided identical grooves, only one of which is sealed to the shell. The system further includes a spring coupled to the compression plate and only one spring interface.

Abstract: Methods and systems for cleaning a capless refueling system in a vehicle are disclosed. In one example approach, a method comprises, in response to a leak detected following a refueling event, cleaning the capless refueling system using engine vacuum.

Abstract: A fuel tank for a hybrid vehicle is disclosed. In one example approach, a fuel tank for a vehicle comprises a wave catcher extending through an interior of the fuel tank and coupled to a front wall and a first side wall of the fuel tank.

Abstract: A system for a vehicle is provided herein. The system includes a fuel vapor canister comprising a shell, a compression plate within the shell and an end cap. The end cap includes a double sided spring interface and a double sided shell sealing surface having double sided identical grooves, only one of which is sealed to the shell. The system further includes a spring coupled to the compression plate and only one spring interface.

Abstract: A distensible fuel tank included in a vehicle, comprising a housing and a compliance structure coupled to the housing, the compliance structure including a support element coupled to a first side of a structural element and a reinforcing element coupled to a second opposing side of the structural element.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments for monitoring fuel system degradation are provided. In one example, a method for a vehicle comprises evacuating fuel from a first fuel tank to a second fuel tank, and indicating fuel system degradation in response to a change in fuel system pressure following the evacuation of fuel. In this way, fuel system degradation may be indicated without use of a separate pressure building device.

Abstract: Systems and methods for operating an engine with a fuel vapor recovery system are disclosed. In one example approach, a method for an engine with a fuel vapor recovery system comprises increasing an amount of flow restriction between storage material in a fuel vapor canister while maintaining a vent valve open during a fuel vapor purging event.

Abstract: A distensible fuel tank included in a vehicle is provided. The distensible fuel tank includes a housing enclosing a lattice structure substantially spanning a portion of an interior defined by the housing, the lattice structure including a plurality of intersecting wall members, at least two of the wall members having an unequal thickness.