A method for ascertaining whether a combustion process is being carried out in a cylinder of an internal combustion engine, it being decided whether or not the combustion process is present as a function of a relative angle between a characteristic signature of a variable characterizing a time curve of a state variable of the internal combustion engine and a specifiable crankshaft angle.

An anomaly diagnosing apparatus is adapted for a cooling device in an internal combustion engine. The apparatus is configured to execute an enlarging process, a rate calculating process, and an anomaly determining process. The enlarging process includes enlarging the cross-sectional area of the flow passage between an inner channel and an outer channel in the cooling device. The rate calculating process includes calculating a reference rate for a rate of rise of temperature of cooling water. The anomaly determining process includes determining that an anomaly is present in the check valve if a rate of rise of a detection value of cooling water temperature is smaller than the reference rate. The rate calculating process includes calculating the reference rate such that the reference rate has a smaller value in a case where the enlarging process is executed than in a case where the enlarging process is not executed.

A method for controlling an engine in a motor vehicle includes determining a theoretical inertia of a drivetrain during a change of an operating mode of the engine, detecting an actual inertia in the drivetrain during the change of the operating mode, and increasing a rotational speed of the engine in response to detecting the actual inertia. The method further includes detecting an inertia overcome, determining a difference between the theoretical inertia and the inertia overcome, and reducing the rotational speed of the engine if the difference becomes less than a threshold value.

In a rotation speed detecting apparatus of an internal combustion engine having a rotor supported by an end part of the crankshaft, a pulser ring that has a detected body composed of recess-projection teeth and rotates integrally with the rotor, and a detector that detects the rotation speed of the crankshaft by detecting the detected body, the detected body has a detected surface opposed to the detector, and the detected surface is inclined in such a manner as to be located closer to the outside of the crankshaft in the axial direction of the crankshaft as getting more apart from an axis line of the crankshaft in the radial direction. In the detector, an axis line of the detector is inclined with respect to the axis line of the crankshaft in such a manner that the detector is opposed to the detected surface.

A test piece characteristic estimation method includes estimating a moment of inertia of a test piece. A first transfer function G1 from a torque current command for a dynamometer to output from a shaft torque sensor is measured by vibrationally operating the dynamometer. A second transfer function G2 from the torque current command to the output of a dynamo rotation speed sensor is measured by vibrationally operating the dynamometer. A real part and an imaginary part of a ratio obtained by dividing the second transfer function G2 by the first transfer function G1 at a prescribed measurement frequency .sub.k are calculated. A moment of inertia Jeg and a rotational friction Ceg are estimated by using the real part and the imaginary part of the ratio.

A current source sensor delivers detection information in the form of an intermediate signal by selectively applying a low-level or high-level current to a communication bus depending on the passage of a mobile target, the sensor including a sensitive portion detecting the passage of a of the mobile target, an electronic module controlling and shape signals coming from the sensitive portion, an embedded intelligence module designed, inter alia, to receive information from another sensor through a first signal present on the communication bus, the first signal being the sum of the abovementioned intermediate signal generated by the sensor and of another intermediate signal generated by the other sensor, wherein the embedded intelligence module is adapted to modify a first low level and a first high level of the intermediate signal, respectively, into a second low level and into a second high level depending on a the first signal.

An apparatus and a method for diagnosing an internal combustion engine for a vehicle, the apparatus encompassing: a recognition device that is embodied to recognize a shutoff operation of the internal combustion engine while the vehicle is being operated in particular in a normal operating mode; a detection device that is embodied to detect, during the shutoff operation, a part or several parts of a curve for a rotation speed or an inter-tooth time of a crankshaft of the internal combustion engine; a comparison device that is embodied to compare at least one feature of the part or the several parts of the curve, in a comparison, with a comparison feature; and a diagnostic device that is embodied to perform, as a function of a result of the comparison, a diagnosis with regard to a compression loss in at least one cylinder.

A method for ascertaining whether a combustion process is being carried out in a cylinder of an internal combustion engine, it being decided whether or not the combustion process is present as a function of a relative angle between a characteristic signature of a variable characterizing a time curve of a state variable of the internal combustion engine and a specifiable crankshaft angle.

The present teaching aims to provide: a cam angle sensor fault diagnosis apparatus for straddled vehicle, capable of detecting a fault of a cam angle sensor installed in a straddled vehicle and guessing a fault place; an engine system; and a straddled vehicle. A cam angle sensor fault diagnosis apparatus for straddled vehicle includes: a cam signal receiving unit connected to a signal output line through which a cam angle sensor outputs a cam signal in accordance with the rotation angle, the cam signal receiving unit being configured to receive a cam signal via the signal output line; a state determination unit that determines one or two fault states of the cam angle sensor from a disconnection state, a power supply fault state, and a ground fault state, distinguishably from the other fault states, in accordance with a signal level of a cam signal received by the cam signal receiving unit; and a signal output unit that outputs a fault signal representing the one or two fault states determined by the state determination unit, in such a manner that the fault signal representing the one or two fault states is different from a fault signal representing the other fault states.

The control apparatus for a vehicle includes a determination unit that determines whether or not a start condition is established, the start condition including when a torque converter is in a lockup state, and when the vehicle is in an accelerating state; and a display control unit that causes an acting number of rotations to be displayed on a tachometer instead of an actual number of rotations when it is determined by the determination unit that the start condition is established. The display control unit calculates the acting number of rotations based on a target value of an input number of rotations of a continuously variable transmission, and varies the acting number of rotations with a rate of change having an absolute value that is greater than an absolute value of a rate of change of the actual number of rotations upon an abrupt change in the target value.