Various embodiments include a method for controlling a tank ventilation valve connected to an intake tract of a turbocharged internal combustion engine via two flush lines, wherein each of the two flush lines includes a respective check valve including: checking whether the respective check valves are in a toggling range; and if the respective check valves are in the toggling range, at least partially closing the tank ventilation valve.

An evaporative emissions control system configured for use with a vehicle fuel tank includes a purge canister, an accelerometer, first and second vent tubes that terminate at first and second vent openings, a first vent valve, a second vent valve, a vent shut-off assembly and a control module. The accelerometer senses acceleration in an x, y and z axis. The first vent valve is fluidly coupled to the first vent tube. The second vent valve is fluidly coupled to the second vent tube. The vent shutoff assembly selectively opens and closes the first and second valves. The control module estimates a location of liquid fuel based on the sensed acceleration from the accelerometer and determines which vent opening is one of submerged and about to be submerged based on the estimated location of the liquid fuel. The control module closes the vent valve associated with the determined vent opening.

Methods and systems are provided for reducing bleed emissions and exhaust emissions from a vehicle that may be operated autonomously as well as part of a car-sharing model. A parking location of the vehicle is selected at the end of a vehicle event requested by an operator as a function of fuel system and evaporative emissions system variables such that the solar loading of the parking location enables reduced emissions. The parking location selection is further coordinated with the pick-up time and location of a subsequent vehicle event requested by another vehicle operator.

An evaporated fuel processing apparatus preventing evaporated fuel from being discharged out of a canister when residual purge gas is made to return to the canister and processed is provided. In the apparatus, an ECU performs residual purge gas processing operation of returning the residual purge gas into the canister and processing during halt of purge control. This operation includes a residual purge gas pressure-feeding process of pressure-feeding the residual purge gas with the air into the canister by the purge pump in a state in which the atmospheric passage is shut off and the purge passage and the second bypass passages are opened and an air discharge process of discharging the air in the canister outside via the atmospheric passage by opening the atmospheric passage while the purge passage and the second bypass passage are shut off.

An evaporated fuel treatment apparatus calculates concentration of purge gas from the characteristics of density of purge gas and the characteristics of a pump discharge pressure with respect to two butane ratios that have been stored in advance and a detected value of the pump discharge pressure detected by a pressure sensor, calculates concentration of purge gas by correcting the concentration of the purge gas based on an A/F detected value in an engine such that a controller controls an open degree of a purge valve and a pump speed of a purge pump during execution of purge control based on the concentration of the purge gas.

Various methods and systems are provided for correcting relative error between a gaseous fuel torque estimate and a liquid fuel torque estimate in a multi-fuel engine. A system (e.g., a system for an engine) may include a controller with computer readable instructions stored on non-transitory memory that when executed during operation of the engine cause the controller to: operate the engine at a first substitution ratio of gaseous fuel and liquid fuel; correct for relative error between a gaseous fuel to torque conversion factor and a liquid fuel to torque conversion factor; and upon correcting for the relative error, operate the engine at a second substitution ratio, higher than the first substitution ratio.

Methods and systems are provided for conducting a diagnostic on a fuel tank isolation valve that regulates a flow of fuel vapors from a fuel tank to an evaporative emissions system. In one example, a method comprises determining whether the fuel tank isolation valve is stuck in a first open position or a second open position based on a time duration between commanding open a canister purge valve to direct fuel vapors to an engine, and an exhaust gas sensor indicating a rich air-fuel ratio. In this way, appropriate mitigating action may be taken in response to the fuel tank isolation valve being stuck in either the first open position or the second open position.

An evaporated fuel processing device includes: a canister configured to adsorb fuel evaporated from a fuel tank; a vapor pipe connecting the fuel tank to the canister; a sealing valve provided in the vapor pipe to be driven by an actuator to quantitatively control an opening degree; and a controller. The controller includes: a restoration detector configured to detect that the supply of power from a battery to the controller is restored after the supply of power from the battery to the controller is cut off; and a restoration actuator configured to drive the actuator so that the sealing valve is fully closed or fully opened when the restoration detector detects that the supply of power is restored.

An evaporative emission control system for a vehicle includes an engine, a fuel tank connected to the engine and a reversible purge pump connected between the fuel tank and the engine. Fuel vapor generated in the fuel tank is supplied to the engine. The purge pump is operable in a first direction to supply the fuel vapor from the fuel tank to the engine and a second direction to supply air to the fuel tank. A purge control valve is connected between the reversible purge pump and the engine to control a flow of the fuel vapor to the engine.

An evaporated fuel processing device that determines whether a normal state is established, by using pressures by a pressure detector while the evaporated fuel processing device shifts between: a first state where a purge passage is opened by a first valve, air passage is opened by a second valve, the purge passage is closed by a third valve, and a pump stops; a second state, after the first state, where the purge passage is opened by the first valve, the air passage is opened by the second valve, the purge passage is closed by the third valve, and the pump is operating; and a third state which takes place after the second state and where the purge passage is opened by the first valve, the air passage is closed by the second valve, the purge passage is closed by the third valve, and the pump stops.