An evaporative emissions isolation module system configured to manage venting on a fuel tank system is disclosed. The isolation module system includes a carbon canister, a multi-valve assembly and a controller. The carbon canister is adapted to collect fuel vapor emitted by the fuel tank and to subsequently release the fuel vapor to the engine. The multi-valve assembly includes a motor drive that rotates a camshaft having at least a first cam and a second cam housed in a manifold. The multi-valve assembly has a first valve and a second valve. The first valve selectively fluidly connects the fuel tank and the carbon canister. The second valve fluidly connects the carbon canister with a vent port defined in the manifold that vents to atmosphere. The controller sends signals to the multi-valve assembly based on operating conditions to open and close at least one of the first and second valves.

An evaporative emissions control system includes a first vent valve configured to selectively open and close a first vent, a second vent valve configured to selectively open and close a second vent, a fuel level sensor configured to sense a fuel level in the fuel tank, a pressure sensor configured to sense a pressure in the fuel tank, an accelerometer configured to measure an acceleration of the vehicle, and a controller configured to regulate operation of the first and second vent valves to provide pressure relief for the fuel tank. The controller is programmed to determine if a refueling event is occurring based one signals indicating the fuel level is increasing, the pressure in the fuel tank is increasing, and the vehicle is not moving, and open at least one of the first and second vent valves based on determining the refueling event is occurring.

A method for checking a measurement of pressure in a fuel tank, implemented in a vehicle having a fuel tank and a fuel vapor breather circuit including: a filter, a tank isolation valve interposed between the tank and the filter, and a purge line, connected to the filter, downstream thereof, a pressure sensor, and a purge valve. The method includes, when the purge valve is closed: measuring a value of the pressure in the tank when the isolation valve is closed, then measuring a temporal extreme value for the pressure in the purge line following an opening of the isolation valve, and determining, from the measured values, that there is an anomaly in the measured pressure in the tank.

A tank venting system for an internal combustion engine includes a tank, which is connected via a tank vent to a sorption reservoir for a temporary storage of fuel from a tank venting flow. A purge air pump is provided for feeding regenerated fuel from the sorption reservoir via a purge air flow into an intake air flow to the internal combustion engine. A controller is configured to control the purge air pump in such a way that the purge air flow can be adjusted with regard to its pressure, its mass and/or its volume, thus ensuring that a metering of the regenerated fuel via the purge air flow into the intake air flow takes place in accordance with an operating state of the internal combustion engine. A method for regenerating a sorption reservoir is also provided.

A method for operating an evaporative emissions control system for use with a fuel tank that stores and delivers fuel to an internal combustion engine is provided. A vent shut-off assembly is provided that selectively opens and closes at least one valve to provide overpressure and vacuum relief for the fuel tank. The vent shut-off assembly selectively vents to a purge canister. The at least one valve is closed whereby vapor is precluded from passing from the fuel tank to the purge canister. A purge event is performed wherein dedicated fresh air is drawn into the purge canister and delivered from the purge canister to the engine.

A pressure relief valve (10, 70) is provided having a first tubing (14a) connectable to a fuel tank (62) and a second tubing (14b) connectable to a fuel vapor treating device (64), the pressure relief valve comprising: an externally actuated (hereinafter EA) valve (20) disposed between the first tubing (14a) and the second tubing (14b) and being configured for pulsed actuation by a controller (28) thereby allowing pulsed fluid flow through a primary port (18a) disposed between the first tubing (14a) and the second tubing (14b).

A fuel tank system constructed in accordance to one example of the present disclosure includes a fuel tank, a purge canister and a valve assembly. The valve assembly can be fluidly coupled between the fuel tank and the purge canister. The valve assembly can include a main valve and a safety check valve. The main valve can have a main valve first port fluidly coupled to an outlet of the fuel tank and a main valve second port fluidly connected to the purge canister. The safety check valve can be configured to move from an open position to a closed position upon a pressure drop at the fuel tank outlet exceeding a predetermined threshold. The safety check valve can have a safety check valve first port fluidly coupled to the outlet of the fuel tank and a safety check valve second port fluidly coupled to the purge canister.

In an evaporative fuel treatment device, a differential pressure specifying unit specifies a differential pressure between a pressure in a diagnosis target system and the atmosphere, and a pressure target setting unit sets a pressure target value so that the differential pressure attains a predetermined differential pressure value. A pump pressurizes or depressurizes the pressure in the diagnosis target system to the pressure target value, and a leakage diagnosis unit performs a leakage diagnosis based on a pressure change relation value related to the pressure change in the diagnosis target system and the leakage diagnosis threshold value. The fuel partial pressure estimation unit estimates a first partial pressure of fuel vapor in the fuel tank from a tank inside concentration and a tank absolute pressure of a specific component. A corresponding partial pressure specifying unit specifies a second partial pressure of the fuel vapor in the fuel tank based on a relation between the tank absolute pressure and the first partial pressure when the second partial pressure of the fuel vapor in the fuel tank when the pressure is increased or reduced to the target pressure value. A comparison unit compares the first partial pressure and the second partial pressure. A correction unit corrects, based on a comparison result of the comparison unit, a leakage diagnosis threshold value or the pressure change relation value used for the leakage diagnosis.

An evaporative emissions control system includes a first vent valve configured to selectively open and close a first vent, a second vent valve configured to selectively open and close a second vent, a fuel level sensor configured to sense a fuel level in the fuel tank, a pressure sensor configured to sense a pressure in the fuel tank, an accelerometer configured to measure an acceleration of the vehicle, and a controller configured to regulate operation of the first and second vent valves to provide pressure relief for the fuel tank. The controller is programmed to determine if a refueling event is occurring based one signals indicating the fuel level is increasing, the pressure in the fuel tank is increasing, and the vehicle is not moving, and open at least one of the first and second vent valves based on determining the refueling event is occurring.

A fuel vapor treatment apparatus is provided with a fuel tank for storing fuel of an internal combustion engine, a canister for adsorbing fuel vapor generated in the fuel tank, a pump for reducing a pressure inside a detection target system including the fuel tank, a pressure detection sensor for detecting the pressure inside the detection target system, and a fluctuation detection unit for detecting a fluctuation width of the pressure inside the detection target system at the time when the pressure inside the detection target system is reduced to a predetermined pressure value.