A method for checking the operation of a high-pressure fuel supply unit for an internal combustion engine, consisting in driving a high-pressure fuel injection pump by a starter, and after the engine is synchronised and fuel injection into the cylinders is shut off, in defining an initial base pressure in a high-pressure rail, in activating the injection pump by issuing successive timing and angle-setting commands, on the basis of the initial pressure, and in comparing the first pressure and the second pressure obtained in the rail by these timing and angle-setting commands, and/or by comparing at least one of the pressures with a reference pressure in order to check the operation of the high-pressure fuel supply unit for the internal combustion engine

Systems and methods for diagnosing operation of an internal exhaust gas recirculation system of an internal combustion engine are presented. The system and method may be applied to conventional or hybrid powertrains having a capability to rotate an engine via an electric machine. The internal exhaust gas recirculation system may be diagnosed based on output of a differential pressure sensor.

A method is presented, wherein a fuel vapor canister heating element is activated during a first condition, which includes an engine-off condition, and atmospheric air is directed through the fuel vapor canister and into an engine intake. Degradation of the fuel vapor canister heating element is indicated based on an output of an engine intake air temperature sensor. In this way, the integrity of the fuel vapor canister heating element can be determined without relying on canister temperature sensors, which may be confounded by the cooling of the fuel vapor canister during fuel vapor desorption.

Methods and systems for operating an engine that includes an electrically operated throttle are disclosed. In one example, mitigating actions are taken in response to degradation of the electrically operated throttle so that the engine may be operated in a way that allows a driver to reach a service area.

When it is detected that an exhaust cut valve is stuck in a closed state, a control device stops feedback control and maintains a wastegate valve in a completely open state in each of an open operation range and a closed operation range. When it is detected that the exhaust cut valve is stuck in an open state, the control device stops the feedback control and maintains the wastegate valve in the completely open state in the closed operation range, whereas the control device performs the feedback control in the open operation range.

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 method of evaluating operability of a gaseous fuel admission valve of an internal combustion engine is disclosed. The method includes operating the internal combustion engine on gaseous fuel by repeatedly actuating the gaseous fuel admission valve. The method further includes measuring a sequence of temporal developments of an electrical operation parameter respectively associated with an actuation of the gaseous fuel admission valve. The sequence includes a first temporal development to be evaluated and a plurality of temporal developments preceding the first temporal development. The method also includes evaluating operability of the gaseous fuel admission valve based on the first temporal development of the measured sequence and at least one of the plurality of preceding temporal developments of the measured sequence.

Methods are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method includes differentiating between degradation of a throttle of the CRV and a position sensor of the CRV based on each of a throttle inlet pressure and commanded position of the throttle of the CRV. The method also includes utilizing output from the position sensor of the CRV in response to the commanded position of the throttle of the CRV.

A method and a computer program for recognizing and differentiating a flow rate error and a dynamic error of an exhaust gas recirculation system (EGR) of an internal combustion engine. Measured and modeled EGR mass flow signals are each subjected to bandpass filtering using time constants optimized for determining flow rate errors and bandpass filtering using time constants optimized for determining dynamic errors. The energy is determined for each of the filtered signals and an energy quotient is computed between the energies of the signals filtered for dynamic errors and the signals filtered for flow rate errors. A dynamic error and a flow rate error of the exhaust gas recirculation may be recognized and differentiated from one another on the basis of the energy quotients.

A failure detection apparatus for fuel systems of an engine includes a first failure determiner executing, while the engine is in each of a first injection form and a second injection form, a failure determination process on the corresponding fuel system, a second failure determiner executing, when the first failure determiner determines occurrence of a failure in one of the injection forms, a failure determination process on the fuel system corresponding to the other injection form, a failure locator determining whether or not the failure has occurred, for each of the fuel systems responsible for the first and second injection forms, based on a result by the second failure determiner, and a purge process prohibiter prohibiting execution of a purge process for the engine. The second failure determiner causes the purge process prohibiter to prohibit execution of the purge process, when executing the failure determination process on the fuel system.