Abstract: A control apparatus for an internal combustion engine has an oxygen storage volume computing unit for computing an oxygen storage volume of a catalyst by using a real air/fuel ratio detected by an air/fuel ratio sensor installed on the upstream side of a catalyst, a center air/fuel ratio representing a stoichiometric air/fuel ratio and an estimated air flow volume or detecting a flow rate of air flowing into the catalyst. A center air/fuel ratio correcting unit for correcting a center air/fuel ratio based on output of a rear air/fuel ratio sensor provided on the downstream side of the catalyst, and an oxygen storage volume computed by an oxygen storage volume computing unit, and the oxygen storage volume computing unit computes an oxygen storage volume by using a center air/fuel ratio corrected by the center air/fuel ratio correcting unit.

Abstract: A diagnostic device and method of an engine exhaust purifying system, which perform active control of an air-fuel ratio and can make diagnosis of air-fuel ratio sensors, catalysts, etc. in the engine exhaust purifying system with high accuracy and reliability while avoiding a worsening of exhaust emissions, an increase of revolution variations, etc.

Abstract: There is provided a control apparatus for a cylinder injection internal combustion engine which suppresses fuel pulsation caused by cam phase deviation and thereby prevents internal combustion engine exhaust deterioration, so that the reliability of a high-pressure fuel system using a high-pressure fuel pump is improved. The control apparatus for a cylinder injection internal combustion engine includes a high-pressure fuel pump that raises the pressure of fuel and discharges the fuel to a fuel rail, and a fuel pressure sensor that detects a pressure of fuel stored in the fuel rail. The control apparatus controls the high-pressure fuel pump based on the fuel pressure detected by the fuel pressure sensor.

Abstract: A diagnostic apparatus for an internal combustion engine, comprising an adjusting device for adjusting a burning condition, a correction device for estimating or detecting an input or an output to and from the internal combustion engine so as to correct at least one of a throttle opening degree, a fuel injection pulse width, a fuel injection timing, an ignition timing and an exhaust gas recirculation quantity, a recording device for recoding a controlled correction value from the correction device at every predetermined time, and a fuel consumption evaluation means for evaluating a fuel consumption of the engine, being based upon the recorded data or log data as to the recorded data, wherein a deterioration of fuel consumption caused by an abnormality of the engine can been soon detected with no affection by an operating condition of the engine and unevenness of component parts.

Abstract: The present invention reduces exhaust emissions at startup, provides improved fuel pressure control performance in a low-load region, and detects high-pressure fuel system abnormalities. Disclosed is a high-pressure fuel system control device which includes a high-pressure pump for pressurizing fuel and discharging the pressurized fuel to a fuel rail, an injector for injecting the fuel stored in the fuel rail, and a fuel pressure sensor for measuring the pressure of the fuel stored in the fuel rail, and controls the high-pressure pump and the injector in accordance with an output generated from the fuel pressure sensor.

Abstract: The present invention provides a vehicle diagnostic system comprising an electronic control unit for controlling and monitoring vehicle equipment, a radio communication means for transmitting a vehicle diagnostic information to a telecommunication equipment located outside the vehicle or for communicating between the vehicle and the telecommunication equipment located outside the vehicle and for transmitting a communication diagnostic signal to the electronic control unit and receiving a response signal to the communication diagnostic signal, and a communication line for connecting the electronic control unit and the radio communication means wherein the response signal is utilized to determine if the communication line is properly functional.

Abstract: A diagnostic apparatus for an internal combustion engine, comprising an adjusting device for adjusting a burning condition, a correction device for estimating or detecting an input or an output to and from the internal combustion engine so as to correct at least one of a throttle opening degree, a fuel injection pulse width, a fuel injection timing, an ignition timing and an exhaust gas recirculation quantity, a recording device for recoding a controlled correction value from the correction device at every predetermined time, and a fuel consumption evaluation means for evaluating a fuel consumption of the engine, being based upon the recorded data or log data as to the recorded data, wherein a deterioration of fuel consumption caused by an abnormality of the engine can been soon detected with no affection by an operating condition of the engine and unevenness of component parts.

Abstract: A diagnostic device and method of an engine exhaust purifying system, which perform active control of an air-fuel ratio and can make diagnosis of air-fuel ratio sensors, catalysts, etc. in the engine exhaust purifying system with high accuracy and reliability while avoiding a worsening of exhaust emissions, an increase of revolution variations, etc.

Abstract: In a diagnosis apparatus for an internal combustion engine which determines the abnormality of a linear A/F sensor which is disposed on the upstream side of a catalyst of the engine and detects the A/F of exhaust gas, the apparatus includes a response/gain deterioration detection unit that separately detects the response deterioration in which the response of the linear A/F sensor is delayed and the gain deterioration in which the detection sensitivity of the linear A/F sensor is abnormal.

Abstract: A diagnostic device and method of an engine exhaust purifying system, which perform active control of an air-fuel ratio and can make diagnosis of air-fuel ratio sensors, catalysts, etc. in the engine exhaust purifying system with high accuracy and reliability while avoiding a worsening of exhaust emissions, an increase of revolution variations, etc.

Abstract: Pressure detection means detects the pressure of an evaporation purge system that includes a fuel tank and a communicating tube, which connects a canister for adsorbing and retaining fuel vapor to an intake pipe. Shutout means shuts out the evaporation purge system from atmospheric air. A pump is driven for pressurization or depressurization purposes while the shutout means shuts out the evaporation purge system from atmospheric air. The pump is stopped when the pressure detected by the pressure detection means reaches a predetermined level. A leak judgment is formulated in accordance with pump drive time and a pressure change after pump stoppage.

Abstract: In a diagnosis apparatus for an internal combustion engine which determines the abnormality of a linear A/F sensor which is disposed on the upstream side of a catalyst of the engine and detects the A/F of exhaust gas, the apparatus includes a response/gain deterioration detection unit that separately detects the response deterioration in which the response of the linear A/F sensor is delayed and the gain deterioration in which the detection sensitivity of the linear A/F sensor is abnormal.

Abstract: The present invention provides a vehicle diagnostic system comprising an electronic control unit for controlling and monitoring vehicle equipment, a radio communication means for transmitting a vehicle diagnostic information to a telecommunication equipment located outside the vehicle or for communicating between the vehicle and the telecommunication equipment located outside the vehicle and for transmitting a communication diagnostic signal to the electronic control unit and receiving a response signal to the communication diagnostic signal, and a communication line for connecting the electronic control unit and the radio communication means wherein the response signal is utilized to determine if the communication line is properly functional.

Abstract: A control apparatus for an internal combustion engine has an oxygen storage volume computing unit for computing an oxygen storage volume of a catalyst by using a real air/fuel ratio detected by an air/fuel ratio sensor installed on the upstream side of a catalyst, a center air/fuel ratio representing a stoichiometric air/fuel ratio and an estimated air flow volume or detecting a flow rate of air flowing into the catalyst. A center air/fuel ratio correcting unit for correcting a center air/fuel ratio based on output of a rear air/fuel ratio sensor provided on the downstream side of the catalyst, and an oxygen storage volume computed by an oxygen storage volume computing unit, and the oxygen storage volume computing unit computes an oxygen storage volume by using a center air/fuel ratio corrected by the center air/fuel ratio correcting unit.

Abstract: A catalyst diagnosis apparatus comprises a reaction rate calculation unit for calculating a reaction rate of chemical reaction in a three-way catalyst based on an output of an oxygen sensor, and an OSC indicator calculation unit for calculating an OSC indicator indicating an oxygen storage capacity (OSC) of the three-way catalyst based on outputs of a linear air-fuel ratio sensor and the oxygen sensor, and a catalyst degradation determination unit for determining degradation of the three-way catalyst based on the reaction rate and the OSC indicator. The determination of the catalyst degradation can be performed with high accuracy in a manner adapted for influences of external environments, etc.

Abstract: In a diagnosis apparatus for an internal combustion engine which determines the abnormality of a linear A/F sensor which is disposed on the upstream side of a catalyst of the engine and detects the A/F of exhaust gas, the apparatus includes a response/gain deterioration detection unit that separately detects the response deterioration in which the response of the linear A/F sensor is delayed and the gain deterioration in which the detection sensitivity of the linear A/F sensor is abnormal.

Abstract: Pressure detection means detects the pressure of an evaporation purge system that includes a fuel tank and a communicating tube, which connects a canister for adsorbing and retaining fuel vapor to an intake pipe. Shutout means shuts out the evaporation purge system from atmospheric air. A pump is driven for pressurization or depressurization purposes while the shutout means shuts out the evaporation purge system from atmospheric air. The pump is stopped when the pressure detected by the pressure detection means reaches a predetermined level. A leak judgment is formulated in accordance with pump drive time and a pressure change after pump stoppage.

Abstract: The present invention provides a vehicle diagnostic system comprising an electronic control unit for controlling and monitoring vehicle equipment, a radio communication means for transmitting a vehicle diagnostic information to a telecommunication equipment located outside the vehicle or for communicating between the vehicle and the telecommunication equipment located outside the vehicle and for transmitting a communication diagnostic signal to the electronic control unit and receiving a response signal to the communication diagnostic signal, and a communication line for connecting the electronic control unit and the radio communication means wherein the response signal is utilized to determine if the communication line is properly functional.

Abstract: A diagnostic device and method of an engine exhaust purifying system, which perform active control of an air-fuel ratio and can make diagnosis of air-fuel ratio sensors, catalysts, etc. in the engine exhaust purifying system with high accuracy and reliability while avoiding a worsening of exhaust emissions, an increase of revolution variations, etc.

Abstract: An exhaust control system for a cylinder fuel injection engine having a cylinder injection injectors directly injecting a fuel into combustion chambers and a catalytic converter provided in an exhaust passage from said combustion chambers for purifying an exhaust gas, such that the air/fuel ratio in the combustion chambers is periodically made richer for quickening activation of catalytic converter.