A device for discharging fuel vapor from a fuel supply system for an internal combustion engine has a container which is situated in the fuel supply system and contains liquid fuel under an upwardly limited pressure. A discharge line, which leads to a tank venting system, leads out of the container. The device also has a detector for detecting vaporous fuel in the container and a blocking device which is coupled to the detector and with which the discharge line can be opened or blocked depending on the detection. A method for discharging fuel vapor from a fuel supply system for an internal combustion engine continuously detects whether vaporous fuel is also present in the container which is situated in the fuel supply system and contains the liquid fuel under an upwardly limited pressure; opens the discharge line if the vaporous fuel has been detected and blocks the discharge line if no vaporous fuel has been detected; and discharges the vaporous fuel through the opened discharge line while retaining the liquid fuel.

Provided is a vehicle control device configured to suppress power to be consumed by an arithmetic device while the vehicle operation is stopped, and to diagnose the operation frequency of the timer for abnormality. The vehicle control device of the present invention allows the bandpass filter to convert the operation frequency of the timer into the voltage value. The holding circuit holds the value corresponding to the converted voltage value. The arithmetic device diagnoses whether or not the timer has been normally operated using the voltage value held in the holding circuit.

A method for operating a vehicle with an internal combustion engine is provided that includes regulating a pressure in a fuel tank by scheduling an engine start-up event based on a rate of change of the fuel tank pressure to reduce fuel tank venting emissions, where the rate of change of the fuel tank pressure is determined based on an ambient temperature and an in-tank pressure.

Methods and systems are provided for preparing an energy receiving apparatus of a vehicle for receiving an increase in a level of energy storage prior to a vehicle reaching an energy replenishment station for receiving the increase. In one example, a method comprises preparing an energy receiving apparatus for receiving an increase in a level of energy storage while the vehicle is traveling to the energy replenishment station, in response to a vehicle operator confirming at the controller an intent to stop at the energy replenishment station to increase the level of energy storage at the energy receiving apparatus. In this way, a time-frame for increasing the energy level increase may be reduced as compared to situations where such preparations are not undertaken.

A mixed fuel amount control system applying active purging includes: a fuel tank in which biofuel and fossil fuel are mixed and stored, an active purging device to supply an evaporated gas evaporated in the fuel tank to an intake pipe, and a concentration sensor to sense a mixing ratio of the biofuel stored in the fuel tank changes. In particular, the flow rate and the concentration of the evaporated gas of the fuel tank flowing into the intake pipe are changed according to a mixing ratio of biofuel and fossil fuel.

A method for operating an internal combustion engine is provided, which has a combustion unit, including a combustion chamber; a fresh gas tract; an exhaust tract, including an exhaust gas sensor integrated therein; and a fuel tank system. During an operation of the internal combustion engine, while purge gas is conducted via a purge gas line a hydrocarbon content of the purge gas is ascertained with the aid of the HC sensor, and the mass flow of the purge gas is also ascertained, and a fuel mass flow introduced into the fresh gas tract is ascertained from these values in combination and a quantity of fuel introduced into the combustion chamber and/or into the fresh gas tract with the aid of at least one fuel injector is adapted.

A control device transmits an opening degree command amount to an actuator to command an opening degree of a sealing valve. The control device learns a valve opening start amount in a learning operation based on the opening degree command amount when pressure of vapor-phase gas in a fuel tank starts to decrease in response to the opening degree command amount that gradually increases from zero. The control device sets a valve opening threshold, which is for determining that pressure of vapor-phase gas has started to decrease, based on a before-learning pressure, which is pressure of vapor-phase gas before the learning operation is started. The control device determines the opening degree command amount based on the valve opening start amount unit when causing the sealing valve to open to perform a vapor operation or a purge operation.

Disclosed is a method for diagnosing sealing in a fuel vapor recirculation system for an engine of a motor vehicle. An electronic module is integrated into the engine control unit that is woken up and placed on standby periodically while the engine is off, at the start and end of time intervals in order to perform a respective leak diagnosis, the fuel vapor temperature Tsys being estimated as a function of a time t ending at the start of each interval and starting when the engine is switched off according to the following equation, in which Tamb is the ambient temperature measured, Tsys0 is the fuel vapor temperature when the vehicle is switched off, and tsys is a system response time:

Tsys(t)=Tamb+(Tsys0−Tamb)e.sup.−t/tsys.

An evaporative fuel processing device includes a canister, a purge path connected to the canister and an intake path that is connected to an internal combustion engine and through which purge gas flows from the canister to the intake path, and a flow control valve provided in the purge path to control the flow rate of the purge gas, wherein: the device further includes a first pressure detection unit that detects a first pressure at a first position between the canister and the flow control vale, and a concentration estimation unit that estimates a purge concentration of the purge gas flowing in the purge path; and the concentration estimation unit determines an increase in the first pressure generated by closing the flow control valve based on the detection value from the first pressure detection unit, and estimates the purge concentration based on the determined increase in the first pressure.

In this evaporated fuel treatment apparatus, there are set a purge condition that is a condition for performing purge control, a first pre purge condition that is met before the purge condition is met, and a second pre purge condition that is met between the purge condition and the first pre purge condition. A purge pump is driven at an idling speed lower than a rated speed to execute idle rotation when the first pre purge condition is met. The purge pump is driven at the rated speed to execute rated rotation when the second pre purge condition is met. A purge valve is opened while the rated rotation is performed when the purge condition is met.