Abstract: In a method for assessing the operating capacity of a lambda control, which outputs regulated values FR which are to fluctuate about a desired regulated value FR.sub.- DES, which lambda control is assisted by an adaptation outputting adaptation values, the current value of a decision quantity, which indicates the averaged absolute value of deviation of the regulated value from the desired regulated value, is calculated continuously, then the current value is compared with a decision-quantity threshold value SW.sub.- EW, and the faulty signal is output when the current value exceeds the decision-quantity threshold value. It is therefore also possible to recognize those fails which occur only in part ranges of the total range in which an internal-combustion engine, in which the fuel supply is set by means of the lambda control, can be operated.

Abstract: The invention relates to an arrangement for monitoring the performance loss of an oxygen probe arranged forward of a catalytic converter. The oxygen probe supplies an actual voltage U.sub.-- ACT for a lambda controller for an internal combustion engine and the arrangement includes: a computation unit for computing the time-dependent mean value .vertline.U.sub.-- ACT-U.sub.-- DES .vertline. of the actual voltage U.sub.-- ACT from a desired voltage U.sub.-- DES; and, an evaluation unit for determining the performance loss of the oxygen probe on the basis of the time-dependent mean value. A simple method sequence which can be carried out with the above arrangement includes the step of deeming the probe to have an impermissibly high performance loss when the above-mentioned mean value drops below a threshold value. However, the quotient is preferably formed between the above-mentioned mean value and the mean value .vertline.FR.sub.-- ACT-FR.sub.-- DES.vertline.

Abstract: A method for alternately carrying out phases with and without tank venting during operation of an internal combustion engine equipped with a tank-venting assembly is characterized in that the ratio of the time spans with and without tank venting is selected to be dependent upon operating data of the engine or of the tank-venting assembly. Preferably, a variable is measured which is a measure for the fuel quantity to be regenerated during tank venting and the above-mentioned ratio is increased in favor of the tank-venting time span with respect to the base ratio when the value of the measured variable exceeds an upper limit (Dp.sub.-- SMW; FTEA.sub.-- SWU). This method makes possible that an adsorption filter and a tank-venting valve in the corresponding arrangement can be dimensioned for lesser throughput quantities than previously without the danger being present that fuel vapors escape to the ambient.

Abstract: The invention is directed to a connecting circuit for a potential-free lambda probe having a ground line and a signal line and having an offset voltage source which is connected to the ground line. This offset voltage source raises the potential of the ground line to a pregiven value relative to ground. A ground short is directly detectable in the connecting circuit of the invention in that the potential measured at the signal line drops below the offset voltage. In this way, it is no longer required as in conventional circuits to check for a ground short by enriching the mixture of an engine and to monitor the exhaust gas with the lambda probe.

Abstract: A method and an arrangement for open-loop control and/or closed-loop control of an operating variable of an internal combustion engine is suggested with a transfer element fixing the relationship between input and output variables in the form of a characteristic curve or characteristic field such as an electrically actuable actuator, which directly or indirectly influences the operating variable of the engine of a motor vehicle and which fixes the relationship between the driving and operating variable or a variable influencing this operating variable in the form of a characteristic curve or a characteristic field. The transfer element or the characteristic curve or the characteristic field is subjected to changes. By adapting the characteristic curve or the computation instruction representing the characteristic curve or the characteristic field, these are adapted to these changes.

Abstract: In the method for the adapted precontrol and feedback control of the air/fuel mixtures to be supplied to the two fuel-metering devices of an internal combustion engine, which has two separate exhaust-gas channels with a lambda probe and a catalytic converter in each channel, a common value of the precontrol manipulated variable and a common lambda desired value are determined for both fuel-metering devices. On the other hand, values of a control manipulated variable are determined separately for each fuel-metering device and values of precontrol adaptation variables, which are dependent upon the values of the control manipulated value, are determined and are superposed separately one after the other on the common precontrol value. This method makes it possible to manage with a single device for both cylinder banks which are to be operated in a stereo lambda control.

Abstract: The invention is directed to a method for obtaining a value for evaluating the performance loss of a catalytic converter with the aid of a forward signal of a forward gas probe mounted forward of the catalytic converter and a rearward signal of a rearward gas probe mounted rearward of the catalytic converter, the catalytic converter being connected to an internal combustion engine. The method includes the steps of: carrying out the method during the steady-state operation of the engine; multiplying the forward signal and the rearward signal with each other to form a plurality of products; averaging the products over a plurality of oscillations of the forward signal to obtain a mean value; and, utilizing the mean value as a value for evaluating the performance loss of the catalytic converter. This correlation method can be varied in different ways and especially in that the forward-probe signal is correlated without or with phase shift with the rearward-probe signal.

Abstract: In a fuel injection system for an internal combustion engine, the system calculates the pulse width of the angle-synchronous fuel injection pulses from a main load sensor, such as an inlet manifold pressure sensor (22) or a hot film or hot wire air mass meter (24). Under rapidly-changing load conditions of the engine, the signal from the main load sensor is not sufficiently accurate to maintain a closely stoichiometric mixture. The present invention provides a throttle valve angle sensor for monitoring the degree of opening of an engine throttle (18), and changes the calculation of the basic angle-synchronous fuel injection signal when the measured rate of change of the throttle valve angle reaches a predetermined valve.

Abstract: A tank-venting arrangement includes: a tank; an adsorption filter connected to the tank; a tank-venting valve interconnecting the adsorption filter and the intake pipe of the engine; a control unit for driving the tank-venting valve so that it closes or opens; a pressure difference sensor for measuring the pressure difference between the pressure in the tank and the ambient pressure; and, an integrating unit for determining the time integral of the pressure difference. With this tank-venting arrangement, a simple and reliable determination can be made as to when so much fuel vapor should have been adsorbed in the active charcoal filter so that when the tank-venting valve is opened thereafter, a lean correction by means of a lambda controller can be required. If this lean correction is not made, this is an indication that the fuel flowing from the tank has not reached the tank-venting valve so that the tank-venting arrangement leaks or is obstructed.

Abstract: The invention relates to a method and an arrangement for checking the operability of an electric heater in motor vehicles and especially the heater of an oxygen probe which is mounted in the exhaust gas channel of an internal combustion engine. It is necessary to determine the temperature-dependent electrical resistance and the temperature of the oxygen probe heater for a precise evaluation of the operational state of the oxygen probe heater. The basic principle of the invention is based upon the consideration that the measurement of the electrical resistance of the oxygen probe heater is then carried out when the oxygen probe heater has cooled down to the ambient temperature. Whether this cool down has taken place can be determined in various ways in accordance with the invention, for example, from the cool down of the engine block or by a comparison of the engine block temperature to the intake-air temperature.

Abstract: The torque of an internal combustion engine is controlled during acceleration by monitoring differences between engine and wheel speed in order to provide a measure of phase differences in the event of the engine torque oscillating. The difference between the engine and wheel signals is integrated and fed to an ignition angle correction circuit in order to damp out the torque oscillations which would otherwise result.

Abstract: The invention is directed to a method of checking a tank-venting apparatus for a motor vehicle equipped with a fuel tank and an internal combustion engine having an intake pipe. The apparatus includes an adsorption filter having a venting end and an intake end, a supply line connecting the intake end to the tank and a connecting line interconnecting the intake pipe of the engine and the intake end of the adsorption filter. A tank-venting valve is mounted in the connecting line between the intake pipe and the intake end of the adsorption filter and a drive unit for actuating the tank-venting valve.

Abstract: The invention is directed to a method for lambda control of an internal combustion engine having a catalyzer and a measuring probe arrangement in front of the catalyzer for emitting a measuring signal and a testing probe arrangement behind the catalyzer for emitting a test signal. The method includes the steps of: forming a ratio between the measuring signal and the test signal at pregiven operating conditions; evaluating said ratio as an estimating quantity for the conversion rate of the catalyzer; and, modifying output values of control parameters in a pregiven controlled manner on the basis of the instantaneous values of said ratio, said output values being applicable for controlling an internal combustion engine having a new catalyzer. This method affords the advantage that it evaluates a catalyzer with the aid of the above-mentioned ratio value and controllably modifies values of control parameters in dependence upon the evaluation ratio.

Abstract: A tank-venting arrangement includes: a tank having a tank closure; an electrically drivable check valve; an adsorption filter; connecting lines for interconnecting the above components; a difference pressure sensor which measures the pressure difference between the pressure in the tank and the ambient pressure and supplies a pressure difference signal; a comparator which, at least for a running engine, compares the pressure difference signal to upper and lower threshold values and supplies an opening signal to the check valve to open the latter when the pressure difference signal is greater than the upper threshold value and a closure signal for closing the check valve when the pressure difference signal drops below the lower threshold value; and, a detector unit which supplies an opening signal to the check valve for opening the check valve when the sensor determines a possible opening of the tank and a closure signal for closing the check valve when the sensor determines a possible closure of the tank.

Abstract: A tank-venting system has an adsorption filter (AF) with a venting line (BL) which can be shut off by means of a controllable shut-off valve (AV). The shut-off venting valve makes it possible to set underpressures and overpressures in the system in a concerted manner in order to check its operability. As a result, particularly reliable information relating to the operability can be obtained.

Abstract: A tank-venting arrangement for a motor vehicle includes a fuel tank KT having a HC (hydrocarbon)-sensor, an adsorption filter AF and a tank-venting valve TEV. If the HC-sensor annouces that fuel vapor above a pregiven concentration is present in the tank, then it is expected that a lambda correction in the lean direction is required when the tank-venting valve is opened. If such a correction is not determined, this shows that either the arrangement leaks or the tank-venting valve does not open correctly. For carrying out the mentioned testing method, this arrangement requires only a single additional sensor, namely, the HC-sensor mounted in the tank. The arrangement is therefore simpler than known arrangements and nonetheless permits carrying out a reliable method for checking the operability.

Abstract: The invention relates to a method and a device for adjusting operating parameters of an internal combustion engine. Time-independent programs are executed in a low-priority background program and programs dependent on the crank angle are executed in a high-priority synchroprogram. Time-dependent programs are divided into different groups, specifically into at least one group of time-dependent programs of shortest interval and at least one composite group which contains the group of time-dependent programs of shortest interval. When a predetermined grid interval has elapsed, a particular group of time-dependent programs, that is either a group of time-dependent programs of shortest interval or a composite group, is run through.

Abstract: A petrol injection system for an internal combustion engine, the system being adapted to provide additional petrol into the inlet manifold of the engine during acceleration conditions in order to compensate for the less efficient transference of vaporized fuel to the engine cylinders during acceleration conditions, the quantity of additional fuel (BA) being determined in accordance with a stored enrichment value (FBAAM) which is adjusted regularly to take into account changing engine conditions. During the warming-up phase of the engine when the normal lambda regulation is inactive, the magnitude and direction of adjustment of the acceleration enrichment value (FBAAM) is derived from the behavior of the rotational speed (n) of the engine and the .lambda. probe signal (.lambda.>1 or .lambda.<1) during an acceleration enrichment operation in that if, during an acceleration enrichment operation in the warming-up phase of the engine, it is detected that the .lambda.

Abstract: An apparatus 14 for adapting the characteristic of an idling adjuster has a release means 15 which allows adaptation only when the sign of a speed control deviation .DELTA.n corresponds to the sign of an air-quantity control deviation .DELTA.Q.This guarantees that the adaptation cannot counteract the speed control either as a result of still insufficient adaptation or by shunt signals from the air-quantity meter 11.

Abstract: A method and an arrangement for carrying out the method are proposed whose fundamental concept is to perform a diagnosis of the heating device of an exhaust-gas probe, which emits a control signal for closed-loop controlling the air/fuel mixture of an internal combustion engine. The diagnosis is based on that the exhaust-gas probe is heated more rapidly because of the switching-in of the heating device than by mere heating by the exhaust gases which flow past the exhaust-gas probe. The heating device includes at least the probe heater, devices which supply the probe heater with the necessary heating power, and the supply leads therefor.