A method for shutting down an electrically controlled component of a vehicle in a case of error of a processing unit, the component being controlled by a control circuit, which receives at least one control signal from the processing unit and controls the component as a function of the at least one received control signal, the processing unit outputting the at least one control signal to a control terminal, the processing unit being designed for outputting an error signal having a defined level to the control terminal in a case of error.

Systems and methods for determining air-fuel error in an engine fueled via direct and port fuel injection. Errors associated with individual fuel injection systems are distinguished from a common error based on trends in the error correction coefficients of the individual fuel injection systems. Adaptive fuel multipliers for each injection system are updated to account for the common error.

An object is to carry out an abnormality diagnosis for a variable compression ratio mechanism without adding any special hardware configuration for estimating a compression ratio. An abnormality diagnostic device for a variable compression ratio mechanism adapted to be applied to an internal combustion engine comprises a controller configured to calculate a predetermined rotational speed difference which is a rotational speed difference, between an engine rotational speed at a predetermined crank angle before or after compression top dead center and an engine rotational speed in the vicinity of the compression top dead center for a predetermined cylinder at the time of carrying out fuel cut processing, set a reference range of the predetermined rotational speed difference, and make a diagnosis that abnormality has occurred in the variable compression ratio mechanism when the predetermined rotational speed difference is out of the reference range.

An engine includes at least one spark plug, an ignition advance management device to determine and to apply an optimum ignition advance of the spark plug, and an exhaust gas recirculation device equipped with a gas recirculation control valve. A control device for the internal combustion engine includes a first actuator to force opening and closing of the control valve, a map in which are stored theoretical ignition advance values as a function of engine speed and engine load, a first calculator to calculate a diagnostic criterion as a function of the theoretical ignition advance determined from the map and the optimum ignition advance, and a comparator to compare the diagnostic criterion to a control valve failure threshold.

Methods and systems are provided for reducing a spark plug soot load and a combustion chamber soot load by controlling spark plug timing while injecting water or washer fluid. In one example, water or washer fluid is injected during a torque reduction while advancing spark timing so as to provide at least a portion of the torque reduction while opportunistically cleaning soot from the spark plug and combustion chamber. By reducing spark plug soot load, misfire occurrence is reduced, while pre-ignition occurrence is reduced by decarbonizing the combustion chamber.

A method for controlling a plurality of injectors installed in the same cylinder of an engine may include determining whether an electrical failure occurred in any of the injectors, and entering a fail-safe mode when an electrical failure has occurred only in one of the plurality of injectors in the same cylinder. In the fail-safe mode, fuel supply to an injector that has experienced an electrical failure is cut off, and the amount of fuel injected into the cylinder by a normally operating injector is increased.

A variety of methods and arrangements for detecting failure of the commanded air induction in an internal combustion engine are described. In some embodiments, the intake manifold pressure is monitored. An air induction event generates a fluctuation in the intake manifold pressure, which is recorded. The signal is processed through a diagnostic filter to help determine whether the actual induction matched the commanded induction. In other embodiments, measured crankshaft acceleration is compared with estimated crankshaft acceleration. If the two quantities differ by a threshold amount an induction fault is detected. The two detection methods may also be combined. The describe approaches are particularly well suited for use in engines operating in a skip fire mode with cylinder deactivation and/or a dynamic firing level modulation mode.

Methods and systems are described for detecting valve actuation faults in internal combustion engines operating in a skip fire operational mode. In one aspect, for each skip fire working cycle, an expected exhaust pressure is determined for a time period corresponding to a potential exhaust event. One or more exhaust gas pressure sensors are then used to measure an actual exhaust pressure during the potential exhaust period. The actual exhaust pressure is compared to the expected exhaust pressure to determine whether a valve actuation fault has occurred. A variety of valve actuation faults can be identified using the described approach. In some embodiments pressure sensors are deployed in the runners of the exhaust manifold.

A method for controlling a position of a flap of a variable port flap control module (VCM) may include determining whether a vehicle state satisfies a predetermined opening condition of the VCM, determining a VCM opening voltage in consideration of tolerance of the flap of the VCM when the vehicle state satisfies the opening condition of the VCM, and controlling the flap of the VCM to be in an opened state by applying the VCM opening voltage to a motor of the VCM when the opening condition of the VCM is satisfied, during an engine starts.

A method for fuel regulation during a non-motoring operating mode of an internal combustion engine is provided. A fuel regulator employs a first fuel to regulate pressure of a second fuel. The first fuel is communicated to the fuel regulator through a first fuel circuit. The method comprises actuating a fuel injector that introduces the first fuel and the second fuel into a combustion chamber of the internal combustion engine during the non-motoring operating mode. The fuel injector is actuated with an injection command signal having a pulse width below a predetermined maximum value whereby no fuel is injected into the combustion chamber and the first fuel drains from the first fuel circuit through the fuel injector to a supply tank.