Abstract: In a method and a device for operating an internal combustion engine, with at least one cylinder (Z1-Z4) having a combustion chamber (26), fuel is injected into the cylinder and a logic value (LV_FCUT) is set, in particular for stopping the injection of fuel into the cylinder, The method furthermore has the following steps: depending on a course of the highly time-resolved measurement signal of a rotational speed (N_FAST) of the internal combustion engine, a local maximum value (N_FAST_MAX) of the rotational speed is determined, a rotational speed difference (N_FAST_DIF) between the local maximum value (N_FAST_MAX) and a current measured value (N_FAST_MES) of the rotational speed is determined, and, depending on the determined rotational speed difference (N_FAST_DIF), the logic value (LV_FCUT) is set.

Abstract: In a method and a device for operating an internal combustion engine, with at least one cylinder (Z1-Z4) having a combustion chamber (26), fuel is injected into the cylinder and a logic value (LV_FCUT) is set, in particular for stopping the injection of fuel into the cylinder, The method furthermore has the following steps: depending on a course of the highly time-resolved measurement signal of a rotational speed (N_FAST) of the internal combustion engine, a local maximum value (N_FAST_MAX) of the rotational speed is determined, a rotational speed difference (N_FAST_DIF) between the local maximum value (N_FAST_MAX) and a current measured value (N_FAST_MES) of the rotational speed is determined, and, depending on the determined rotational speed difference (N_FAST_DIF), the logic value (LV_FCUT) is set.

Abstract: In a method for determining, whether a crankshaft of a combustion engine rotating forward after a reverse rotation is oscillating or continues the forward movement, when noticing a reverse rotation of the crankshaft, the covered rotational angle during a reverse rotation is detected, an actual threshold is computed by adding the covered rotational angle and a predetermined safety distance. The rotational angle of the crankshaft rotating immediately forward after a reverse rotation is compared to the actual threshold.

Abstract: In a method and a device for operating an internal combustion engine, with at least one cylinder (Z1-Z4) having a combustion chamber (26), fuel is injected into the cylinder and a logic value (LV_FCUT) is set, in particular for stopping the injection of fuel into the cylinder, The method furthermore has the following steps: depending on a course of the highly time-resolved measurement signal of a rotational speed (N_FAST) of the internal combustion engine, a local maximum value (N_FAST_MAX) of the rotational speed is determined, a rotational speed difference (N_FAST_DIF) between the local maximum value (N_FAST_MAX) and a current measured value (N_FAST_MES) of the rotational speed is determined, and, depending on the determined rotational speed difference (N_FAST_DIF), the logic value (LV_FCUT) is set.

Abstract: In a method for determining, whether a crankshaft of a combustion engine rotating forward after a reverse rotation is oscillating or continues the forward movement, when noticing a reverse rotation of the crankshaft, the covered rotational angle during a reverse rotation is detected, an actual threshold is computed by adding the covered rotational angle and a predetermined safety distance. The rotational angle of the crankshaft rotating immediately forward after a reverse rotation is compared to the actual threshold.

Abstract: Method for determining the timing of an indirect injection internal combustion engine, in which the following steps are performed: use is made of a first sensor (2) including a target (6) connected to the crankshaft and having a plurality of marks (8), use is made of a second sensor (12) including a target (16) connected to the camshaft and having: a plurality of teeth (D1, D2, D3), a plurality of gaps (C1, C2, C3), and a plurality of fronts (F1, F2, F3, F4, F5, F6) separating the teeth (D1, D2, D3) and the gaps (C1, C2, C3), the engine is turned over from a starting position, the marks (8) on the target (6) of the first sensor (2)are counted, the fronts (F1, F2, F3, F4, F5, F6) on the target of the second sensor are detected, this is used to deduce the engine timing.

Abstract: Method for determining the timing of an indirect injection internal combustion engine, in which the following steps are performed: use is made of a first sensor (2) including a target (6) connected to the crankshaft and having a plurality of marks (8), use is made of a second sensor (12) including a target (16) connected to the camshaft and having: a plurality of teeth (D1, D2, D3), a plurality of gaps (C1, C2, C3), and a plurality of fronts (F1, F2, F3, F4, F5, F6) separating the teeth (D1, D2, D3) and the gaps (C1, C2, C3), the engine is turned over from a starting position, the marks (8) on the target (6) of the first sensor (2) are counted, the fronts (F1, F2, F3, F4, F5, F6) on the target of the second sensor are detected, this is used to deduce the engine timing.

Abstract: According to this method, a) a series of sparks is emitted into an engine cylinder (1), filled with an air/fuel mixture to be ignited, at predetermined successive instants, b) one of the sparks that initiates the ignition of the mixture is identified, c) the difference separating the instant of emission of the spark from a predetermined ignition instant able to ensure that the engine supplies a predetermined mechanical power is evaluated, and d) the instant of opening of the fuel injector (3) is corrected as a function of the difference, so as to initiate subsequent ignitions of the air/fuel mixture in the cylinder (1) at the predetermined instant.

Abstract: According to this method, a) a series of sparks is emitted into an engine cylinder (1), filled with an air/fuel mixture to be ignited, at predetermined successive instants, b) one of said sparks that initiates the ignition of said mixture is identified, c) the difference separating the instant of emission of said spark from a predetermined ignition instant able to ensure that said engine supplies a predetermined mechanical power is evaluated, and d) the instant of opening of said fuel injector (3) is corrected as a function of said difference, so as to initiate subsequent ignitions of the air/fuel mixture in said cylinder (1) at said predetermined instant.

Abstract: Method for correcting the signal (30) of a sensor corresponding to the passage of teeth (20b) and of hollows (20d) of a target (20) secured to an engine camshaft, characterized in that duration measurement is used to evaluate the angular values (&agr;T,&agr;N) of the alternations (30b, 30d) of the signal corresponding to the teeth and to the hollows, these angular values are compared with the mechanical angles (&ggr;T,&ggr;N) of the teeth and of the hollows, and from this a phase shift (&agr;1,&agr;2) of the rising (30a) and falling (30c) fronts of the signal with respect to the corresponding flanks (20a, 20c) of the teeth of the target is deduced. When said teeth and hollows extend over equal angular sectors, the phase shifts are calculated directly by comparing the duration measurements of two consecutive alternations (30b, 30d) of the signal.

Abstract: Method for correcting the signal (30) of a sensor corresponding to the passage of teeth (20b) and of hollows (20d) of a target (20) secured to an engine camshaft, characterized in that duration measurement is used to evaluate the angular values (&agr;T, &agr;N) of the alternations (30b, 30d) of the signal corresponding to the teeth and to the hollows, these angular values are compared with the mechanical angles (&ggr;T,&ggr;N) of the teeth and of the hollows, and from this a phase shift (&agr;1,&agr;2) of the rising (30a) and falling (30c) fronts of the signal with respect to the corresponding flanks (20a, 20c) of the teeth of the target is deduced. When said teeth and hollows extend over equal angular sectors, the phase shifts are calculated directly by comparing the duration measurements of two consecutive alternations (30b, 30d) of the signal.

Abstract: A symmetrical voltage divider whose tap is supplied with a reference voltage via a resistor is connected between the terminals of an inductive sensor. A diagnostic voltage is applied to the tap. Using evaluation devices, the diagnostic voltage is compared with two threshold values in a stationary state, and then sampled in the operational state, and a difference is calculated from the largest and smallest sampled, values and is compared with a third threshold value. Short circuits or line interruptions are detected from the comparison result and are displayed.