Abstract: A method for controlling and regulating the combustion in the combustion chamber of an internal combustion engine, at least one knock sensor detecting a cylinder-specific knocking signal for each cylinder of the internal combustion engine, the knocking signal detected in this manner being fed to an evaluation circuit which reconstructs the combustion chamber pressure characteristic from the detected knocking signal, this combustion chamber pressure characteristic being evaluated for the control and regulation of the next combustion in this cylinder.

Abstract: The invention is directed to a method for detecting combustion misfires in a multicylinder internal combustion engine. The method includes the steps of: forming a criterion for the rough running of the engine for each cylinder individually on the basis of time intervals during which the crankshaft passes through predetermined angular ranges; and, forming corrective values from rough-running values for each cylinder individually during misfire-free operation so that the rough-running values for each individual cylinder coupled to said corrective values become equal with respect to each other.

Abstract: A method of determining diagnostic threshold values for a particular motor vehicle type is proposed, the motor vehicles of the motor vehicle type being equipped with an electronic computing unit and the electronic computing unit having a programmable memory module and a microcomputer, as well as an interface for data communication with an external computer. The diagnostic data of each available motor vehicle of the particular motor vehicle type are transmitted to an external central computer and stored there in a database of the central computer. Then a statistical distribution is formed on the basis of the diagnostic data compiled there. Then at least one diagnostic threshold value for a certain diagnostic data item is established on the basis of this statistical distribution. A suitable electronic computing unit, which programs the newly established diagnostic threshold values into the programmable memory module, is likewise proposed.

Abstract: The invention is directed to a method for detecting combustion misfires in a multicylinder internal combustion engine. The method includes the steps of: detecting the time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (.phi.) for each ignition of the engine; computing a vector element Lut(i) for the rough running of the engine based on at least one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with the two vector elements Lut(i), Lut(j) being for each ignition (i); computing the spacing between the vector LUT(i) and at least one predetermined reference vector Rn and Ra; and, detecting a combustion misfire when the spacing satisfies a predetermined condition.

Abstract: A transmitter wheel is used for example to detect speed changes of an internal combustion engine with high precision in order to calculate a running imbalance value from them. A transmitter wheel of this kind has for example three segments, which are ideally the same length, but in reality usually have lengths which differ slightly from one another. In order to prevent measurement errors which are caused by this, it is known to determine the actual lengths by means of an adaption process. The device according to the invention is embodied such that for each segment, it has a plurality of adaption filters to detect different adaption values for different speed ranges. It has namely turned out that in different speed ranges, different lengths are measured, which is an error that must be compensated for since the length of a segment is in fact actually constant.

Abstract: The invention is directed to a method for detecting combustion misfires in an internal combustion engine on the basis of a first signal wherein the nonuniformity of the rotational movement of the crankshaft of the engine is imaged. The method includes the steps of: generating a second signal which is periodic and has a period duration corresponding to one of the following: the cycle duration of a complete work cycle of the engine or the cycle duration divided by a whole number, and the second signal having a fixed phase relationship to the rotational movement of said crankshaft; providing an ancillary signal based on the first signal; modulating the second signal with the ancillary signal and filtering the second signal to form a third signal; and, utilizing the third signal for detecting the presence of misfires and for identifying the cylinder affected by the misfires.

Abstract: A method is proposed for monitoring operations of an internal combustion engine to detect combustion misses for internal combustion engines having dual spark coils. A method is provided for the primary-side monitoring of the spark voltage and/or of the spark duration, and a method is provided for detecting irregular operations. If a faulty ignition is detected in one cylinder at one spark plug by monitoring the spark voltage and/or the spark duration, the second spark plug in this cylinder is then cut off (de-energized) and the reaction to this cut-off is monitored by means of the method for detecting irregular running. If the irregular running detection confirms faulty operation of the internal combustion engine, then the faulty ignition at the first spark plug of a cylinder was correctly recognized and appropriate emergency measures are introduced.

Abstract: The invention is directed to a method of checking the tightness of exhaust valves of an internal combustion engine with the aid of an apparatus. The apparatus includes a device for forming a value LU for the uneven running of the engine and a device for metering air into a region disposed downstream of the exhaust valves as viewed in the flow direction of the exhaust gas. In the method, a first value LU1 is formed for the uneven running without air being supplied in the above-mentioned region and a second value LU2 is formed for uneven running with air being supplied in the above-mentioned region. An exhaust valve is deemed to leak when the first and the second values for the uneven running differ by more than a predetermined amount.

Abstract: A method for monitoring a system for delivering secondary air to an exhaust tube of an internal combustion engine. In the method a secondary air pump is switched on and builds up a pressure on the inlet side of a blocking valve which is normally closed and not being acted upon. The blocking valve has a valve closing member that is acted upon by a predetermined closing force of an elastic element. If the secondary air quantity pumped by the secondary air pump reaches a certain minimum air quantity and pressure, then with the then-opened blocking valve, a lambda sensor disposed in an exhaust tube detects a change in the lambda value in the exhaust tube that exceeds a predetermined threshold value. The method is suitable for monitoring the function of a system for delivering secondary air to the exhaust tube of an internal combustion engine.

Abstract: An apparatus for monitoring a system for delivering secondary air to an exhaust tube of an internal combustion engine. In the method and apparatus, a secondary air pump is switched on and builds up a pressure on the inlet side of a blocking valve which is normally closed and not being acted upon. The blocking valve has a valve closing member that is acted upon by a predetermined closing force of an elastic element. If the secondary air quantity pumped by the secondary air pump reaches a certain minimum air quantity and pressure, then with the then-opened blocking valve, a lambda sensor disposed in an exhaust tube detects a change in the lambda value in the exhaust tube that exceeds a predetermined threshold value. The apparatus is suitable for monitoring the function of a system for delivering secondary air to the exhaust tube of an internal combustion engine.

Abstract: The signal from a vibrationally-sensitive pressure sensor is both low-pass filtered and band-pass filtered. The low-pass-filtered portion is employed as a pressure-measuring signal, while the band-pass filtered portion is used as an acceleration-measuring signal. The pressure sensor is preferably installed in the tank-venting installation of a motor vehicle to measure the pressure differential relative to the surroundings. The acceleration-measuring signal is used to stop a recognition of engine misfiring, as soon as a rough road surface is recognized as a result of this signal.

Abstract: A tank-venting system has the following features: a tank 10; an adsorption filter 13 which is connected to the tank via a tank-connecting line 12 and which has a venting line 14 which can be closed off by a shut-off valve 15; and, a tank-venting valve 16 which is connected to the adsorption filter via a valve line 17; a pressure connection 21 on the valve line close to the tank-venting valve; and, a pressure sensor 11 on the tank.With the aid of this tank-venting system, the following method can be carried out: closing the tank-venting valve and the shut-off valve; supplying compressed air to the pressure connection; measuring the pressure in the tank; and, checking if the pressure satisfies a pregiven pressure condition and determining the tank-venting system as being inoperable in the event that this is not the case.

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: A temperature-dependent base desired value for the opening angle is determined in a method for precontrolling the opening angle of a throttle flap during the idle engine-speed control of an internal combustion engine. This temperature-dependent base desired value is then modified within a start-time duration. The modification takes place in that, during start, a temperature-dependent angle increase is determined which is multiplied by a time-reduced multiplier factor and the product is additively superposed on the base desired value. With this procedure, and notwithstanding the simple method sequence, it is ensured that the start phase of a warm internal combustion engine takes place without engine-speed increases. It is especially advantageous to modify additional engine-speed base desired values in a corresponding manner. In this case, hardly any additional measures must be undertaken which go beyond those which must be undertaken to modify the base desired value for the opening angle of the throttle flap.

Abstract: The invention is directed to a system for setting the throttle flap angle for an internal combustion engine. The system sets the idle stop for the idle throttle flap angle and monitors the setting with respect to defects that occur. If the throttle flap is in contact engagement with the idle stop, a contact is actuated which causes a buffer storage of the actual throttle flap angle which thereby represents the position of the idle stop. If then, for example, the idle stop changes during driving operation, its new position is established upon a renewed contact engagement of the throttle flap, by measuring the throttle flap angle. A possible defect can be established from a comparison of actual and desired values and a positioning motor is then appropriately driven to displace the idle stop. This system has the advantage that a defect occurring in the region of the positioning motor is detected without additional circuit complexity.

Abstract: In a method for the malfunction testing of an idling control arrangement for an internal combustion engine, the closing function of the idling contact is checked. As soon as it is established that the contact should really be closed but that this is not the case, it is certain that there is either an interruption in the idling contact circuit or a servomotor fault. In order to be able to distinguish which of these faults is present, a test movement sequence is carried out in which the servomotor of the arrangement is activated and a check is made whether the throttle flap angle changes. If this is not the case, the servomotor is defective; otherwise, an interruption in the idling contact circuit is present. Using this method, it is for the first time possible to detect interruption and servomotor faults. Until now, it was only possible to detect short-circuit faults.

Abstract: The invention is directed to an arrangement for adjusting an operating characteristic quantity of an internal combustion engine such as for the idle speed control with a redundant drive. Two windings of the drive are driven via two separate lines from two separate output stages. When a defect is detected via an electrical monitoring unit, a safety logic unit transfers the full operation for the drive of the throttle flap to the output stage and the winding corresponding thereto which are not affected by the defect. In this way, a noraml idle speed of the engine is assured even in the presence of a single defect.

Abstract: To prevent change of data in a non-volatile programmable, ready-only memory (25) forming, together with a microprocessor (23) a control unit, for example for an automotive vehicle, while permitting programming of the memory from an external programming unit (P, 1), an interface (3, 11, 12) is provided through which a release-enable bus (13) also passes, data being transmitted in accordance with a predetermined characteristic--even or odd parity--, the parity correctness being checked. If the parity is correct, an "enter" signal is provided on the release-enable bus for storing the data; if not, retransmission is attempted for a predetermined number of time, and if it cannot be correctly effected, a malfunction indication output signal is generated.

Abstract: To permit continued operation of a vehicle in spite of malfunction of an electronic ignition computer system, or any other electronic control module in an automotive vehicle, a transducer (10) provides an output to a trigger stage which has its output connected a digitally operating microprocessor (17) and to a bypass or transfer switch (21). The output from the microprocessor is connected to an analog and operating output stage (19, 20) to be controlled by the digital system of the microprocessor (17). Upon sensing of low operating voltage (U) as determined, for example, by a threshold switch (22), or of starting condition the switch (21) is closed, bypassing or interrupting connection to the microprocessor, and directly connecting signals from the transducer output stage to the input of the ignition circuit to permit operation under emergency conditions.

Abstract: A countdown counter (14) counts out a speed dependent number to determine the start of the dwell period when a comparison number (Z17) is reached which is adjusted dynamically by a regulation counter (17). The countdown counter's contents are reduced by a value dependent upon acceleration when acceleration is present in order to improve the dynamic correction. In the case of strong accelerations these dynamic corrections are insufficient and when such a strong acceleration occurs the regulation counter content is set to a high value to assure a succession of strong ignition sparks. The high value of acceleration necessary for this precaution may be determined by comparing the difference of successive engine speed counts with a predetermined value or it may be determined by the failure of the current in the ignition coil primary to reach some predetermined value.