Honda Giken Kogyo Kabushiki Kaisha

Takashi Isobe

Kojiro Tsutsumi

Takashi Yamaguchi

Manabu Niki

Satoshi Kiso

Hiroyuki Ando

Takashi Iwamoto

Hideyuki Oki

Fumio Hara

Hiroshi Yatani

Yukio Miyashita

Koichi Yoshiki

Tetsuya Ohno

Takushi Toda

Atsushi Izumiura

Yuzuru Koike

Atsushi Kurauchi

Kotaro Miyashita

Akira Hashimoto

Eisaku Gosho

Hirofumi Mutoh

A fault determining apparatus for a variable valve timing mechanism is provided for shortly and accurately determining a fault even at low oil temperatures. The mechanism is driven by an oil pressure to change a cam phase of an intake cam and/or an exhaust cam with respect to a crank shaft of an internal combustion engine, thereby controlling the actual cam phase to reach a target cam phase. The apparatus has a fault determining routine executed by an ECU (electric control unit) for determining that the mechanism is faulty when a cam phase difference between the target cam phase and the actual cam phase is not within a predetermined range, an oil temperature sensor for detecting the temperature of the working oil, and a correcting routine executed by the ECU for correcting the predetermined range in an increasing direction when the detected oil temperature is low.

Fault determining apparatus, fault determining method and engine control unit for variable valve timing mechanism

An abnormality detecting device for an evaporative fuel processing system is disclosed. The evaporative fuel processing system includes a fuel tank, a canister for trapping evaporative fuel generated in the fuel tank, a charging passage for connecting the fuel tank and the canister, a tank pressure regulating valve provided in the charging passage, a bypass passage bypassing the tank pressure regulating valve, a bypass valve provided in the bypass passage, and a pressure sensor provided in the fuel tank or in the charging passage at a position between the tank pressure regulating valve and the fuel tank. The pressure in the canister is reduced to a pressure which is lower than the atmospheric pressure in the condition where a valve closing command signal for the bypass valve is output. It is determined that the tank pressure regulating valve or the bypass valve is abnormal, when the pressure detected by the pressure sensor becomes equal to or less than a predetermined threshold during execution of the pressure reduction in the canister.

Abnormality detecting device for evaporative fuel processing system

A system for discriminating malfunction of a radiator of an internal combustion engine, in which conditions for execution of malfunction discrimination of the radiator are decided to be established, when a decline amount of outside air temperature is less than a threshold value, and the malfunction discrimination is conducted by comparing an estimated and detected coolant temperatures with predetermined values. In the system, making the decision that the conditions are not established is prevented, utilizing a parameter related to a quantity of intake air. With this, it becomes possible to inhibit decisions finding that the conditions are not established in certain cases in which such a decision would ordinarily be unreasonably made, such as when the internal combustion engine is started while still insufficiently soaked, etc., so that heat in the intake manifold installed with the outside air temperature sensor causes a transient or momentary decline in the outside air temperature sensor detection value during high-load operation immediately after engine starting.

System for detecting malfunction of internal combustion engine radiator

A failure diagnosis apparatus for diagnosing a failure in an evaporative fuel processing system is disclosed. The evaporative fuel processing system has a fuel tank, a canister containing an adsorbent for adsorbing evaporative fuel generated in the fuel tank, an air passage connected to the canister and communicating with the atmosphere, a first passage for connecting the canister and the fuel tank, a second passage for connecting the canister and an intake system of an internal combustion engine, a vent shut valve for opening and closing the air passage, and a purge control valve provided in the second passage. The purge control valve and the vent shut valve are closed when stoppage of the engine is detected and it is determined whether there is a leak in the evaporative fuel processing system according to the detected pressure in the evaporative fuel processing system during a predetermined determination time period after closing the purge control valve and the vent shut valve. The leak determination of the evaporative fuel processing system is inhibited when the difference between the gas layer temperature and the ambient temperature detected upon stoppage of the engine is less than or equal to a predetermined threshold.

Failure diagnosis apparatus for evaporative fuel processing system

There is provided a leakage determination system for an evaporative fuel processing system, which, even when pressure within the evaporative fuel processing system is temporarily increased e.g. due to an increase in the amount of generation of evaporative fuel in a fuel tank, is capable of performing an accurate leakage determination by eliminating the influence of the temporary rise in the pressure within the evaporative fuel processing system on the leakage determination. A pressure sensor detects pressure within the evaporative fuel processing system. Negative pressure is introduced from the intake system into the evaporative fuel processing system, whereby the pressure within the evaporative fuel processing system is reduced until the detected pressure becomes equal to a predetermined negative pressure. After the pressure reduction, the negative pressure is introduced from the intake system into the evaporative fuel processing system under predetermined conditions. Whether or not there is a leak in the evaporative fuel processing system is determined based on a state of the pressure within the evaporative fuel processing system, which has been detected during the introduction of the negative pressure from the intake system.

Leakage determination system for evaporative fuel processing system

An abnormality detecting device for an evaporative fuel processing system is disclosed. The evaporative fuel processing system includes a fuel tank, a canister for trapping evaporative fuel generated in the fuel tank, a charging passage for connecting the fuel tank and the canister, an on-off valve provided in the charging passage for opening and closing the charging passage, and a pressure sensor provided in the charging passage at a position between the on-off valve and the fuel tank. A pressure in the canister is reduced to a pressure which is lower than the atmospheric pressure in the condition where the on-off valve is open. The on-off valve is closed at the time of completion of the pressure reduction, and it is determined that the charging passage is clogged between the pressure sensor and the fuel tank, when an amount of change in pressure detected by the pressure sensor is less than a predetermined change amount after closing the on-off valve.

A leak determining apparatus for an evaporated fuel treatment system is provided for executing a leak determination for an evaporated fuel treatment system without suspending it even in such a condition that variations in fuel could occur, thereby accurately providing a leak determination result. The leak determining apparatus calculates a reference differential pressure difference DDPZ as a difference between differential pressures of an inner tank pressure PTANK detected at two times in a leak check mode, i.e., a differential pressure DPZ2 and a differential pressure DPZ1 detected a predetermined slosh determination time before, and compares the reference differential pressure difference DDPZ with a slosh determining threshold value DDPZG to determine the presence or absence of sloshing. When the sloshing occurs, the leak determining apparatus calculates a second differential pressure DP2 using an inner tank pressure PTANK corrected with a slosh correction value DDPZHOSEI, and executes a leak determination based on the second differential pressure.

Leak determining apparatus, leak determining method, and engine control unit for an evaporated fuel treatment system

A control system is disclosed that accelerates the rise in temperature of a catalyst provided in an exhaust system of an internal combustion engine. The system increases the intake air amount after the engine starts and retards the ignition timing according to a rotational speed of the engine. In this control system, a failure of the catalyst temperature rise acceleration control is diagnosed according to the engine rotational speed and/or a retard amount of the ignition timing during the execution of the catalyst temperature rise acceleration control. The above failure may also be diagnosed according to at least one of the ignition timing and the engine rotational speed when decreasing the intake air amount during the execution of the catalyst temperature rise acceleration control. The above failure may also be diagnosed according to a detected catalyst temperature and an estimated catalyst temperature.

Control system for internal combustion engine

There is provided a failure determination apparatus which is capable of determining the failure of a temperature sensor promptly and correctly regardless of environmental conditions at the start of an internal combustion engine. An ECU calculates an operation progress parameter indicative of a degree of progress of operation of the internal combustion engine from the start thereof. A RAM of the ECU stores a value of the temperature detected by the temperature sensor at a stoppage of the engine. Further, the ECU measures a stop time period from the stoppage to a start of the engine, and determines that the temperature sensor is faulty, when the difference between a value of the temperature detected by the temperature sensor at the start of the present operation of the engine and the value of the temperature stored in the RAM is equal to or smaller than a predetermined reference value on condition that the operation progress parameter calculated during the immediately preceding operation of the engine is larger than a predetermined value, and that the stop time period before the present operation of the engine is longer than a predetermined time period.

Failure determination apparatus and method and engine control unit for determining a failure of a temperature sensor

A control system of an internal combustion engine in a vehicle, for improving the self-diagnosis accuracy and decreasing the frequency of stopping the self-diagnosis process, is disclosed. The system comprises a self-diagnosis section for executing self-diagnosis of the internal combustion engine; a load control section for controlling a load imposed on the internal combustion engine; and a normal driving control section for maintaining a normal driving state in which a variation of the load imposed on the internal combustion engine is suppressed, by operating the load control section while the self-diagnosis is being executed by the self-diagnosis section and while the current driving state of the vehicle is in a predetermined driving range.

Control system and method of internal combustion engine, for suppressing load variation and improving self-diagnosis

A fuel supply control system for controlling a fuel amount to be supplied to an internal combustion engine having an exhaust gas recirculation mechanism comprising an exhaust gas recirculation passage connected between an intake pipe and an exhaust pipe, and an exhaust gas recirculation valve provided in the exhaust gas recirculation passage, is disclosed. The fuel amount to be supplied to the engine is corrected according to a pressure difference between an intake pressure detected when opening the exhaust gas recirculation valve and an intake pressure detected when closing the exhaust gas recirculation valve.

Fuel supply control system for internal combustion engine

An abnormality diagnosis apparatus for performing a leak check of an evaporative fuel processing system which includes a fuel tank, a canister for storing evaporative fuel generated in the fuel tank, a purging passage for connecting the canister to an intake system of an internal combustion engine, and a purge control valve provided in the purging passage. A process of reducing the pressure in the evaporative fuel processing system is executed with a limited flow rate of gases passing through the purge control valve when performing the leak check in an idling condition of the engine. The limited flow rate is set to a value equal to or smaller than a predetermined flow rate which is smaller than the maximum flow rate applied to the leak check performed in operating conditions other than the idling condition. The leak check is performed on the basis of a change in the pressure in the evaporative fuel processing system after the pressure reduction process.

Abnormality diagnosis apparatus for evaporative fuel processing system

When a leakage fault occurs in the evaporated fuel processing system of a fuel tank, a control system reliably prevents leakage of the evaporated fuel from the point where the leakage fault has occurred. The fuel tank and a canister are connected to each other via a charge passage having a bypass valve, and the canister and an intake passage of an engine are connected to each other via a purge passage having a purge control valve. When a leakage fault occurs in the fuel tank (or the charge passage upstream of the bypass valve), the bypass valve and the purge control valve are opened and an atmosphere release control valve provided on the canister, is closed. The closure of the atmosphere release control valve stops the negative intake pressure of the engine from being consumed by the intake of air through the atmosphere release control valve, and thus it is possible to efficiently prevent the evaporated fuel from leaking from the point where the leakage fault has occurred by effectively transmitting the negative intake pressure to the point where the leakage fault has occurred.

Growing community of inventors

Wako, Japan

Takashi Isobe