Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Junya Kitada

Hideo Matsunaga

Satoshi Maeda

Katsuhiro Furuta

Yuji Sato

Hitoshi Kamura

Shigetoshi Hirano

Koji Kawakita

Shoya Tano

Kazumichi Takahashi

Kenta Imaoka

Control apparatus for an engine includes a failure determination unit which determines whether there is a failure in an operating engine, and an A/F (air-fuel ratio) feedback control unit which performs feedback control to bring actual A/F in the engine to a target set in advance. The failure determination unit includes a failure determination section, a failure code storing section, a similar operating condition recording section, and a return-to-normal control section. The A/F feedback control unit includes an A/F target setting section, and the target set is stored in the similar operating condition recording section as a factor defining the operating condition of the engine. The return-to-normal control section eliminates the failure code if the failure determination section does not determine that there is a failure when the engine is operating in an operating condition similar to that recorded in the similar operating condition recording section.

Control apparatus for engine

A diagnostic device incorporates a processor and a memory and diagnoses a failure related to a fuel injection system for an engine whose air-fuel ratio of is feedback-controlled. The diagnostic device includes a calculation unit which calculates a corrected value of a fuel injection amount according to a difference between a target value and a measured value of the air-fuel ratio. The diagnostic device includes a setting unit which sets a mask period in which a failure diagnosis is suspended, according to the corrected value upon switchover of a fuel injection mode. The diagnostic device includes a diagnostic unit which does not carry out the diagnosis in the mask period and carries out the diagnosis outside the mask period.

Diagnostic device

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.

Failure detection apparatus for fuel systems of engine

A failure determination apparatus for an oxygen concentration sensor disposed downstream of a catalyst provided in an exhaust system is provided for detecting a failure in the oxygen concentration sensor. The failure determination apparatus comprises: a failure determination device for determining a failure in the oxygen concentration sensor based on the length of a period when the output of the oxygen concentration sensor passes through a predetermined output section during enrichment control after a fuel cut mode of the internal combustion engine is released; a rich fuel supply amount calculation device for calculating the time average of an enriching fuel supply amount, relative to a fuel supply amount necessary for stoichiometric combustion, based on an actual fuel supply amount during the enrichment control; and a failure determination restriction device for restricting failure determination of the failure determination device based on the time average of the enriching fuel supply amount.

Failure determination apparatus for oxygen concentration sensor

A deterioration determination unit determines whether a catalyst in an exhaust passage of an engine is deteriorated; a first determination unit determines whether there is an air-fuel ratio variation among cylinders of the engine on the basis of distortion in waveform of the air-fuel ratio on the upstream side of the catalyst; and a second determination unit determines whether there is an air-fuel ratio variation among the cylinders on the basis that the air-fuel ratio on the downstream side of the catalyst remains on the lean side. A determination mode switching unit makes the first determination unit execute a determination process concurrently with determination by the deterioration determination unit, and it is determined by the determination process that there is an air-fuel ratio variation among the cylinders, makes the second determination unit execute a determination process in priority to determination of deterioration of the catalyst.

Failure detection device of internal combustion engine

A first temperature sensor measures a first temperature of an object related to an engine. A fuel temperature sensor measures a fuel temperature. A diagnostic apparatus includes a diagnostic unit diagnosing the first temperature sensor based at least in part on the first temperature measured at the first temperature sensor. The diagnostic apparatus also includes a first determining unit determining whether the state of fault of the first temperature sensor is unclear or not based at least in part on the variation in the fuel temperature after the start-up of the engine for the diagnosis at the diagnostic unit.

Diagnostic apparatus for temperature sensor

A control device for an engine includes an air-fuel ratio detector detecting an air-fuel ratio of an exhaust gas of the engine. A feedback controller performs a feedback control of an amount of a fuel injection of mixed fuel including alcohol so that the air-fuel ratio detected by the air-fuel ratio detector is come close to a target air-fuel ratio, the mixed fuel supplied from a fuel feeder. A concentration estimator estimates a concentration of the alcohol in the mixed fuel based on the air-fuel ratio of the exhaust gas and a correction amount for the amount of the fuel injection controlled by the feedback control. A malfunction determiner determines that the fuel feeder has a malfunction when the correction amount is greater than or equal to a value for a period which is longer than a first period in a second period. The second period is from a first time point when the feedback controller starts to perform the feedback control.

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Tokyo, Japan

Junya Kitada