Abstract: A method for operating an internal combustion engine is described, in which the ambient pressure is determined by an ambient pressure sensor and the pressure in an intake manifold of the internal combustion engine is determined by an intake manifold pressure sensor. In this method the reliability performance of the ambient pressure sensor is checked by comparing the ambient pressure to a starting value that is obtained by the intake manifold pressure sensor before a starting process of the internal combustion engine. The comparison is only performed if a preceding check of the intake manifold pressure sensor yields the result that it is operational.

Abstract: A method and a device for operating an internal combustion engine having an intake manifold and a ventilation system may allow a reliable and fault-free diagnosis of a fault in the ventilation. The ventilation system may be a tank ventilation or a crankcase ventilation. The ventilation duct is conducted to the intake manifold of the internal combustion engine. At least one pressure differential may be determined between an intake-manifold pressure or an ambient pressure, on the one hand, and a pressure in the ventilation duct, on the other hand. A fault in the ventilation may be diagnosed as a function of the at least one pressure differential.

Abstract: A method for operating an internal combustion engine is described, in which the ambient pressure is determined by an ambient pressure sensor and the pressure in an intake manifold of the internal combustion engine is determined by an intake manifold pressure sensor. In this method the reliability performance of the ambient pressure sensor is checked by comparing the ambient pressure to a starting value that is obtained by the intake manifold pressure sensor before a starting process of the internal combustion engine. The comparison is only performed if a preceding check of the intake manifold pressure sensor yields the result that it is operational.

Abstract: The invention is directed to a method for operating an internal combustion engine including an actuating member in an air supply for adjusting an air mass to be supplied to the engine. In the method, a position of the actuating member is adapted to an instantaneous operating state by a short-time adaptation and a position of the actuating member is adapted by a long-time adaptation to compensate for longer term influences on the position of the actuating member. For a long-time adaptation, a long-time adaptation value is formed for the position of the actuating member in dependence upon a minimum short-time adaptation value for the position of the actuating member which was formed during the short-time adaptation. A leakage in the air supply is diagnosed in dependence upon the long-time adaptation value.

Abstract: A method and a device for operating an internal combustion engine having an intake manifold and a ventilation system may allow a reliable and fault-free diagnosis of a fault in the ventilation. The ventilation system may be a tank ventilation or a crankcase ventilation. The ventilation duct is conducted to the intake manifold of the internal combustion engine. At least one pressure differential may be determined between an intake-manifold pressure or an ambient pressure, on the one hand, and a pressure in the ventilation duct, on the other hand. A fault in the ventilation may be diagnosed as a function of the at least one pressure differential.

Abstract: The invention is directed to a method for operating an internal combustion engine including an actuating member in an air supply for adjusting an air mass to be supplied to the engine. In the method, a position of the actuating member is adapted to an instantaneous operating state by a short-time adaptation and a position of the actuating member is adapted by a long-time adaptation to compensate for longer term influences on the position of the actuating member. For a long-time adaptation, a long-time adaptation value is formed for the position of the actuating member in dependence upon a minimum short-time adaptation value for the position of the actuating member which was formed during the short-time adaptation. A leakage in the air supply is diagnosed in dependence upon the long-time adaptation value.

Abstract: A method for recognition of the power stroke of an internal combustion engine is proposed, in which recognition as to whether a cylinder is currently in the power stroke is possible by means of camparison of a signal that is synchronous with the crankshaft angle and a signal that is modulated by the combustion events of the engine.

Abstract: A first control unit of a multiple function control system for a motor vehicle engine controls a function, such as fuel injection, for which it is desirable to provide an engine load signal measured by the amount of air drawn or forced into the engine per unit of time, determined by what is generally known as an air quantity meter. A second control unit of the control system controls the timing of an electrical ignition system for which it has been conventional to supply an engine load signal derived from a pressure transducer.