Denso Corporation

Nippondenso Co., Ltd.

Tatsuya Oka

Keiji Wakahara

Akira Ichikawa

Hisashi Iida

Masakazu Yamada

Syujiro Morinaga

Yukihiro Yamashita

Yoshihiro Majima

Yoshinori Maegawa

Naoyuki Kamiya

Yasuomi Imanaka

Toshifumi Hayami

Atsushi Iwami

Yuji Kaji

Hideyuki Maeji

Ryo Tamura

Takanori Takahashi

Masayuki Tsutsumi

Yuuta Kawashima

An ignition system has an ignition plug and an ignition control unit that controls the ignition plug. When an engine is in a predetermined operating state, the ignition control unit performs ignition control after top dead center to perform ignition after the compression top dead center. The ignition system has an airflow support structure that facilitates the flow of airflow through a discharge gap at least after the compression top dead center. The ignition system is configured such that due to the airflow support structure and the timing of the ignition, airflow at a flow rate of 5 m/s or more flows through the discharge gap during a spark period after top dead center, which is the generation period of the discharge spark in the ignition control after top dead center.

Ignition system

An engine control system has a self-diagnosis function of an exhaust system. The self-diagnosis function includes a first mode for detecting a failure or abnormality of the exhaust system as a whole, and a second mode for determining and locating a specific failed component in the exhaust system. The first mode is executed during the engine is operated under a normal condition. Therefore it is possible to detect the failure of the exhaust system without lowering a drive performance or increasing emissions. In case of detecting any failure in the first mode, the second mode is activated in response to a command signal that can be entered via a service tool. In the second mode, the engine is operated in order to determine the failed component. In the second mode, determining the failed component takes priority over keeping the drive performance or reducing emissions.

Apparatus and method for diagnosis of vehicular system

An emission control system has a catalyst and a sensor responding to a component of exhaust gas. In order to speed warming up the catalyst, the emission control system increases the amount of heat dissipated by exhaust gas. A diagnosis of the emission control system is carried out by determining whether the amount of heat dissipated by exhaust gas is sufficient or insufficient. The amount of heat dissipated by exhaust gas is represented by the length of time to an activated state of the sensor. In the diagnosis, the amount of heat generated by a heater provided in the sensor is taken into consideration.

Emission control system with catalyst warm-up speeding control

A malfunction of a thermostat in a coolant circulating path is detected from an engine side coolant temperature in consideration of the following behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes different considerably from that in the normal time in the temperature range in which the thermostat is to be normally closed. When a closure-malfunction occurs, the coolant temperature becomes different considerably from that during the normal time in the temperature range in which the thermostat is to be normally opened. Alternatively, the malfunction may be detected from a difference between the engine side coolant temperature and a radiator side coolant temperature.

Thermostat malfunction detecting system for engine cooling system

A thermostat malfunction detecting system is provided for detecting a malfunction of a thermostat in a coolant circulating path based on an engine side coolant temperature. When an open-malfunction of the thermostat occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be closed. When a closure-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times that which the thermostat is expected to be opened. As an alternative, the malfunction may be detected from the difference from the engine side coolant temperature and the radiator side coolant temperature.

Malfunction of an engine coolant thermostat is detected from the engine side coolant temperature by the subsequent behavior of the coolant temperature. When an open-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be closed. When a closure-malfunction occurs, the coolant temperature becomes considerably different from that normally expected for times at which the thermostat is expected to be opened. Alternatively, the malfunction may be detected from the difference between the engine side coolant temperature and the radiator side coolant temperature.

An internal combustion engine control apparatus is provided which is capable of performing various controls based upon the air quantity immediately after a current heated element of a hot wire air flow meter is heated to a predetermined temperature. When a key switch is rotated to an 'ON' position, a large current flows through the air flow meter and the detected intake air quantity greatly exceeds the actual intake air quantity and therefore during the warm up period of the heater, the fuel injection amount is a constant corresponding to the coolant temperature until the engine speed reaches 500 rpm. Likewise during this warm up period, the smoothing processing of the fuel injection quantity is stopped. The fuel injection amount is switched from the constant value during starting to a variable quantity corresponding to air flow quantity when the output value of the air flow meter is less than a predetermined value and the engine speed is greater than 500 rpm or a predetermined time has elapsed since the key switch has been 'ON'.

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Kariya, Japan

Tatsuya Oka