Abstract: During the starting of an internal combustion engine with fuel injection, so-called preliminary injections (I) are dispensed according to a certain preliminary injection strategy in order to build up a wall film in the cylinders and simultaneously provide an ignitable mixture for the initial combustion. To avoid a situation where the preliminary charges during the starting phase are too rich or too lean, different quantities of fuel are chosen for the preliminary injections (I) in the case of the method according to the invention, depending on the charges to be expected in the relevant cylinders.

Abstract: A correction factor takes into account the possible change in the quality of the fuel fed to an internal combustion engine between shut-down and restarting of the internal combustion engine. The correction factor is applied to the basic injection time period in the internal combustion engine. The correction factor is weighted with a weighting factor that is selected as a function of the filling level of a fuel reservoir container holding the fuel when the internal combustion engine is shut down, and of the filling level when the internal combustion engine is restarted.

Abstract: During the warm-up phase of a catalytic converter, the fuel-oxygen ratio in the exhaust gas upstream of the catalytic converter is regulated in dependence on the temperature of the catalytic converter. The amount of fuel is measured on the basis of an injection time into the internal combustion engine. The injection time is calculated from a basic injection time weighted with a weighting factor. The weighting factor depends on the secondary air mass which is delivered to the exhaust gas duct and on a predetermined set value for the fuel-oxygen ratio of the exhaust gas (.DELTA.value) upstream of the catalytic converter. The secondary air mass is regulated in dependence on an engine air intake.

Abstract: The tank venting system is evacuated by the negative pressure prevailing in the intake pipe of the internal combustion engine. A regression calculation, based on a physical model which simulates the pressure variation in the event of a leak in the tank venting system, on the basis of a gas mass flow flowing through an opening, supplies a parameter which describes the curve variation of the pressure during the test for gassing out fuel and during the diagnosis. The parameter contains the information about the leak area and takes into account external influences that interfere with the signal evaluation.

Abstract: A diagnostic device for monitoring an exhaust gas recirculation system determines a diagnostic value of the exhaust gas recirculation system without influencing the operation of the internal combustion engine. The diagnostic value depends on the intake pipe pressure and an observer intake pipe pressure. The latter is determined by an observer from one or more further operating variables of the internal combustion engine. The diagnostic device determines that the exhaust gas recirculation system is defective when the diagnostic value lies outside a range of values that depend on at least one operating variable.

Abstract: A method for avoiding misdetection in a diagnosis of a tank venting system for a motor vehicle includes deriving a statement about a fill level of a fuel tank by evaluating a signal of a pressure sensor in the tank venting system. To that end, prior to the diagnosis of the tank venting system, the pressure fluctuations are detected and compared with a threshold value. If the pressure fluctuations exceed the threshold value, then a conclusion is drawn that the fuel tank is full, and the diagnosis is not enabled.

Abstract: A secondary air pump communicates through an air duct with an exhaust gas line of an internal combustion engine. A catalytic converter for cleaning exhaust gas is connected in the exhaust gas line. The secondary air mass pumped by the secondary air pump is measured with an air flow rate meter. A control unit compares the measured secondary air mass with the desired secondary air mass set by the control unit. If the measured secondary air mass differs from the set secondary air mass by more than a specified amount, then the control unit has detected a malfunction.

Abstract: A method for monitoring functional capability of a tank venting system for a motor vehicle, includes evacuation of the tank venting system through the use of negative pressure or vacuum prevailing in the suction tube of an internal combustion engine and assessing the system based on negative pressure buildup and negative pressure letup gradients. Additionally, besides other abnormal termination criteria, the dynamics of pressure changes are also monitored and the method is immediately discontinued, if pressure fluctuations are ascertained which exceed a predetermined measure.

Abstract: A tank venting system for trapping fuel vapors and feeding the fuel vapors to an internal combustion engine having a fuel tank and an intake tube, includes a container adsorbing fuel vapors. A venting line is connected between the fuel tank and the container. A regeneration line is connected between the container and the intake tube of the internal combustion engine. A ventilation line communicates with the atmosphere and the container. A ventilation valve closes the ventilation line. A tank venting valve is disposed in the regeneration line and is triggered in an opening direction for feeding fuel vapors stored in the container. A pressure sensor detects a system pressure of the tank venting system. A method for monitoring the tank venting system includes monitoring the system pressure with the pressure sensor during the feeding of the fuel vapors, categorizing the ventilation valve as functioning improperly if a predetermined pressure threshold value is exceeded, and closing the tank venting valve.