Japan Electronic Control Systems Company, Limited

Unisia Jecs Corporation

Akihiko Araki

Shinpei Nakaniwa

Junichi Furuya

Masanobu Ohsaki

Yukio Hoshino

Masanobu Osaki

Mitsuru Miyata

Toshio Namba

Michiyuki Fujimoto

A diagnostic system for detecting a freezing condition of an intake pressure sensor for an engine includes a control unit for checking engine operating parameters after a turn-on of an ignition switch to determining whether the engine is a predetermined state permitting a freeze diagnosis, and for performing the freeze diagnosis only when the engine is in the predetermined state. The control unit monitors a decrease of the intake pressure sensed by the intake pressure sensor as the engine speed increases from a start, and judges a freezing condition to exist if the intake pressure does not become sufficiently low even after the engine speed becomes higher than a predetermined speed level.

Diagnosis for detecting freezing condition in intake pressure sensor

Secondary air is supplied to a position upstream of a catalyst disposed in an exhaust passage of an engine. An oxygen sensor is disposed between a secondary air supply portion of the exhaust passage and the catalyst. The supply amount of the secondary air is feedback controlled so that the oxygen concentration in the exhaust gas detected by the oxygen sensor approaches a target value corresponding to a theoretical air/fuel ratio. A second oxygen sensor for air/fuel ratio control is disposed upstream of the secondary air supply portion. Air/fuel ratio feedback control adjusts the air/fuel ratio of air entering the engine so that the oxygen concentration at the second oxygen sensor approaches the same target value as at the other oxygen sensor.

Method and system for controlling secondary air for internal combustion

In a method and system for controlling an engine idling speed applicable to an internal combustion engine, a pulse duty ratio of a pulse signal supplied to an engine idling control valve is set by adding a basic control value, a proportional constant, and integration constant. The integration constant, set according to a difference between a target engine idling speed and an actual engine revolution speed, is modified as follows; during normal engine idling, the integration constant is set according to which one of the compared values of the target engine idling speed and actual engine revolution speed is greater. However, when an external load is applied to the engine, the integration constant is set by a quantity corresponding to the proportional constant.

System and method for controlling engine idling speed applicable to

In order to reduce erroneous ignition timing to the maximum possible degree, an arbitrary point is defined between the trailing edge of a basic control pulse and TDC. The ADV at which ignition should occur is determined to be advanced or retarded with respect to the same. If it is found that the ADV is advanced with respect to the arbitrary point where a calculation, which is initiated at the trailing edge of the basic control pulse cannot be completed in time, a time period from the leading edge is derived and a counter started. Alternatively, if a count is not proceeding and a trailing edge is detected, a second time is derived and the counter started. If it is found that the counter is running but the degree of ignition advance is such as to fall between the leading and trailing edges of the basic reference control pulse, the count is stopped and ignition immediately induced.

Internal combustion engine ignition timing device

A fuel injection control system derives a correction coefficient for compensating overshooting component in measurement of an engine load indicative parameter, such as an intake air flow rate. The correction coefficient may be variable in such a manner that it increases according to increasing of the engine load. The correction coefficient may be used for correcting either the measured engine load parameter or the fuel injection amount derived taking the measured engine load.

Fuel injection control system for internal combustion engine with

An air/fuel ratio control system is designed for detecting small deceleration and subsequently detecting small magnitude acceleration. When small magnitude acceleration is detected, a LAMBDA control correction value which is utilized for deriving fuel injection amount, is fixed at a predetermined value for a predetermined period. The air/fuel ratio utilized during the aforementioned period is set at a value greater than the instantaneous value at a timing at which a demand for small magnitude acceleration is detected.

Air/fuel ratio control system for fuel injection internal combustion

A spark ignition control system distinguishes engine operating condition between low engine load range where acceleration shock tends to be created and high engine load range where acceleration shock to be created is small and better acceleration characteristics is required. The spark ignition timing control system performs spark advance retarding control while the engine is in the low engine load range and in response to acceleration demand. On the other hand, the spark advance retarding control is disabled in the high engine load range.

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Gunma, Japan

Akihiko Araki