Abstract: To achieve a reliable and exhaust-optimized combustion starting already from the beginning of a combustion phase in the startup of an internal combustion engine, the internal combustion engine is brought to a target speed by an electric motor in a drag phase, the target speed being higher than the previously known starting speed. The target speed corresponds approximately to an idling speed assigned to the internal combustion engine, for example. After exceeding the starting speed, first a mixture enrichment is determined, taking into account a prevailing state of a wall film here in particular. Only after reaching the target speed is the fuel metered and does the combustion take place in the combustion phase. The fuel is metered here in particular on the basis of the mixture enrichment determined after exceeding the starting speed.

Abstract: Method and apparatus for detecting tank leaks, in which a gas pressure acts on a fluid which is situated in a tank, and in which the gas pressure in the tank or tank system is changed, wherein a tank leak is detected by evaluation of a temporal profile of a sum pressure of the fluid which is situated in the tank.

Abstract: A procedure to diagnose a fuel tank ventilation system of a motor vehicle and a device to implement the procedure are proposed. The fuel tank ventilation system contains at least one first ventilation pathway discharging into the air intake area of the internal combustion engine downstream behind a supercharger as well as at least one second ventilation pathway discharging into the air intake area upstream in front of the supercharger. Provision is made for a diagnosis with at least two partial diagnoses, whereby the first partial diagnosis pertaining to the first ventilation pathway is implemented, if the intake manifold pressure in the discharge area of the first ventilation pathway is smaller than the fuel tank system pressure; and the second partial diagnosis pertaining to the second ventilation pathway is implemented, if the intake manifold pressure in the discharge area of the first ventilation pathway is greater than the fuel tank system pressure.

Abstract: A method of diagnosing a fuel tank leak in a fuel tank ventilation system, comprising a fuel tank, an accumulator for fuel vapors and a fuel tank ventilation valve opening out into an intake manifold of an internal combustion engine, wherein the fuel tank, the accumulator and the fuel tank ventilation valve are connected by way of a system of lines and wherein the accumulator has an aeration line with a check valve, the method comprising: immediately before turning off the internal combustion engine, closing the check valve and opening the fuel tank ventilation valve to generate a vacuum in the fuel tank ventilation system; acquiring a vacuum degradation at specifiable points in time when the fuel tank ventilation valve is closed; opening of the check valve in order to bring about a pressure equilibrium with the ambient pressure; renewed closing of the check valve; acquiring a pressure increase emerging over at least a specifiable time interval and determination of a compensation variable; and inference about

Abstract: A method and a device for operating a drive unit of a vehicle are provided, which result in reduced fuel consumption in the overrun condition. An output variable of the drive unit is set, in this context, according to a preset driving strategy in the overrun condition of the drive unit. At least two preset driving strategies are specified for the overrun condition of the drive unit. In the overrun condition, one of the specified driving strategies is selected as a function of a driving situation.

Abstract: The invention concerns a procedure to heat up or keep warm an exhaust gas emission control assembly of a motor vehicle with a drive train containing one transmission. The drive train is powered by an internal combustion engine and at least one second drive unit. It is proposed that also in an operating state, which lies outside of the idle speed, a rotational speed or a torque of the internal combustion engine deviating from values for the engine rotational speed and the torque is set, which would exist during an identical driving condition without the heating-up or keeping warm of the exhaust gas emission control assembly.

Abstract: A procedure to diagnose a fuel tank ventilation system of a motor vehicle and a device to implement the procedure are proposed. The fuel tank ventilation system contains at least one first ventilation pathway discharging into the air intake area of the internal combustion engine downstream behind a supercharger as well as at least one second ventilation pathway discharging into the air intake area upstream in front of the supercharger. Provision is made for a diagnosis with at least two partial diagnoses, whereby the first partial diagnosis pertaining to the first ventilation pathway is implemented, if the intake manifold pressure in the discharge area of the first ventilation pathway is smaller than the fuel tank system pressure; and the second partial diagnosis pertaining to the second ventilation pathway is implemented, if the intake manifold pressure in the discharge area of the first ventilation pathway is greater than the fuel tank system pressure.

Abstract: A method of and an apparatus for checking the tightness of a tank system of an internal combustion engine of a motor vehicle by means of overpressure or underpressure, in which a first controllable valve is disposed in a connection between the tank system and an overpressure or underpressure source, and a second controllable valve is disposed in a connection of the tank system with the ambient air in which the leak testing is performed at the end of a phase of operation of the engine, in particular at the end of a travel mode, of a motor vehicle that has the engine, and a demand for shutoff of the engine is executed with a time delay, and at least the steps of the leak testing that generate the overpressure or underpressure are performed within the delay time.

Abstract: In a method for testing the functional reliability of a fuel-tank venting valve which is provided in a tank system of a motor vehicle in particular, is connected to an intake manifold and is triggerable by a control unit, a pressure source is provided for testing the tank system for leaks by using excess pressure or a vacuum, and the test of the functional reliability of the fuel-tank venting valve is performed on the basis of at least one performance quantity of the pressure source. In order to achieve a short diagnostic time and a high degree of diagnostic certainty, the fuel-tank venting valve is triggered to open or close, and a certain change in pressure is implemented. The at least one performance quantity of the pressure source is detected, and a properly opening and closing fuel-tank venting valve is determined from the performance quantity thus detected.

Abstract: The invention relates to a method and an arrangement for monitoring the operability of a secondary air system of an internal combustion engine having an exhaust-gas system. The secondary air system includes a secondary air pump. In the method and arrangement, a signal is determined which characterizes the secondary air flow. In the method, at least one signal of at least one operating characteristic variable of the secondary air pump is determined during the determination of the signal characterizing the secondary air flow and a conclusion is drawn as to a fault in the secondary air system when the signal of the at least one operating characteristic variable lies outside of a pregiven interval. The at least one signal of at least one operating characteristic variable is determined in dependence upon the operating state of the engine. This signal is determined from a signal for the pump current of an electrically operated secondary air pump.

Abstract: In order, in a diagnostic unit for leak testing of a tank system of an internal combustion engine, to allow minimization of the energy consumption during a diagnostics test and simultaneously prevent the emission of fuel gases, a sleep/wake-up mechanism is provided. The diagnostic unit enters a sleep mode for a selected time interval after the internal combustion engine is turned off, the diagnostic unit enters a wake-up mode at the end of the first time interval and at least acquires the measurement data necessary for the diagnostics test in the wake-up mode. The diagnostic unit then enters the sleep mode again during the diagnostics period. The diagnostic unit is switched off at the end of the diagnostics period.

Abstract: A drive unit includes an engine and a transmission having a variable transmission ratio. An instantaneous setpoint power output quantity of the drive unit is determined from an intended power output. The setpoint power output quantity is a function of the instantaneous transmission ratio of the transmission at least for a given intended power output.

Abstract: In a method for testing the functional reliability of a fuel-tank venting valve which is provided in a tank system of a motor vehicle in particular, is connected to an intake manifold and is triggerable by a control unit, a pressure source is provided for testing the tank system for leaks by using excess pressure or a vacuum, and the test of the functional reliability of the fuel-tank venting valve is performed on the basis of at least one performance quantity of the pressure source. In order to achieve a short diagnostic time and a high degree of diagnostic certainty, the fuel-tank venting valve is triggered to open or close, and a certain change in pressure is implemented. The at least one performance quantity of the pressure source is detected, and a properly opening and closing fuel-tank venting valve is determined from the performance quantity thus detected.

Abstract: The invention relates to a method and an arrangement for monitoring the operability of a secondary air system of an internal combustion engine having an exhaust-gas system. The secondary air system includes a secondary air pump. In the method and arrangement, a signal is determined which characterizes the secondary air flow. In the method, at least one signal of at least one operating characteristic variable of the secondary air pump is determined during the determination of the signal characterizing the secondary air flow and a conclusion is drawn as to a fault in the secondary air system when the signal of the at least one operating characteristic variable lies outside of a pregiven interval. The at least one signal of at least one operating characteristic variable is determined in dependence upon the operating state of the engine. This signal is determined from a signal for the pump current of an electrically operated secondary air pump.

Abstract: In a method and a device for leak testing of a vessel, e.g., a tank venting system of a motor vehicle, a leak-tightness measurement is performed by introducing a positive pressure or partial vacuum and detecting the variation over time of a positive pressure or partial vacuum in the vessel, and a reference measurement is performed using a reference leak. A conclusion is drawn as to the presence of a leak in the vessel by comparing the results of the leak-tightness measurement and the reference measurement. To avoid faulty diagnoses, the positive pressure or partial vacuum during the leak-tightness measurement and the reference measurement is detected by using a single pressure measuring device.

Abstract: The invention relates to a method for checking the tightness of a vessel and especially of a tank-venting system of a motor vehicle. In the method, at least a reference leak (42) or the vessel is subjected to an overpressure or underpressure with at least one pressure source. At least one characteristic variable of the pressure source is determined (reference measurement or diagnostic measurement) and these characteristic variables are compared to each other and a conclusion is drawn as to the presence of a leak from the result of the comparison. The pumping power of the at least one pressure source is changed during the reference measurement and/or during the diagnostic measurement.

Abstract: In a method for checking the tightness of a tank-venting system of a vehicle, one tightly closes the tank by means of a blocking device after shutting off the vehicle. Thereafter, one detects the pressure, which develops in the tank system, with a pressure sensor and draws a conclusion as to a leak based on the pressure trace over time. An arrangement for checking the tightness in accordance with this method is suggested.

Abstract: The arrangement for operating a fuel tank system of a motor vehicle includes a pump and valve arrangement (11), an activate charcoal filter (12), a fuel supply tank (14) and a control unit (20). In addition, safety valves (31, 32) as well as a pressure switch (33) are provided. The arrangement (11) includes a de-energized bistable magnetic valve (40) which is connected via a line (41) to the control unit (20) and is driven via a control module (42). The control unit (20) is connected via lines (43, 44) to pressure and/or temperature sensors (45, 46). The pressure sensors (45, 46) supply pressure signals to the control unit (20) via the lines (43, 44).

Abstract: In order, in a diagnostic unit (70) for leak testing of a tank system (10) of an internal combustion engine, to allow minimization of the energy consumption during a diagnostics test and simultaneously prevent the emission of fuel gases, a sleep/wake-up mechanism (270, 300, 350) is described, in which the diagnostic unit (70) enters a sleep mode for a selected time interval after the internal combustion engine is turned off, the diagnostic unit (70) enters a wake-up mode at the end of the first time interval and at least acquires the measurement data necessary for the diagnostics test in the wake-up mode; the diagnostic unit (70) then enters the sleep mode again during the diagnostics period, and the diagnostic unit (70) is switched off at the end of the diagnostics period.

Abstract: The invention relates to a method for checking the tightness of a vessel and especially of a tank-venting system of a motor vehicle. In the method, at least a reference leak (42) or the vessel is subjected to an overpressure or underpressure with at least one pressure source. At least one characteristic variable of the pressure source is determined (reference measurement or diagnostic measurement) and these characteristic variables are compared to each other and a conclusion is drawn as to the presence of a leak from the result of the comparison. The pumping power of the at least one pressure source is changed during the reference measurement and/or during the diagnostic measurement.