Abstract: 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.

Abstract: An abnormality detecting apparatus for an intake system of an internal combustion engine, which detects an abnormality of the intake system, is disclosed. The intake system has a throttle valve, a bypass passage bypassing the throttle valve, and an idling control valve for controlling the amount of air supplied through the bypass passage to the engine. A total intake air amount supplied to the engine is calculated. An amount of intake air supplied through the bypass passage is calculated based on a valve opening control quantity for the idling control valve. A parameter indicative of a leak air amount of the intake system is calculated according to the result of a comparison between the calculated total intake air amount and the amount of intake air supplied through the bypass passage.

Abstract: A failure detection apparatus for a cooling system of an internal combustion engine is disclosed. The cooling system has a radiator, a cooling water pipe for circulating a cooling water in the engine to the radiator, and a thermostat provided in the cooling water pipe for opening and closing the cooling water pipe. An estimated cooling water temperature of the engine is calculated according to the engine operating condition. The estimated cooling water temperature is compared with a determination threshold set according to the detected vehicle speed at the time the detected cooling water temperature has exceeded a predetermined water temperature. If the estimated cooling water temperature is lower than or equal to the determination threshold, it is determined that the thermostat is normal.

Abstract: 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.

Abstract: There is provided a power output control system for an internal combustion engine, which enables the vehicle to smoothly perform refuge travel to find a place to park when an electric throttle control device becomes incapable of controlling a throttle valve, while ensuring adequate traveling performance. An ECU determines whether or not the electric throttle control device is incapable of controlling the throttle valve, and interrupts energization of the electric throttle control device when it is determined that the electric throttle control device is incapable of controlling the throttle valve. At this time, the opening of the throttle valve is held at the default opening degree by a spring. Further, basic ignition timing is calculated according to the engine rotational speed and load on the engine, and ignition timing of the engine is determined by correcting the calculated basic ignition timing according to the amount of operation of the accelerator pedal.

Abstract: 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.

Abstract: 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.

Abstract: There is provided a control system for a vehicle, which enables the vehicle to smoothly travel only to find a place to park when an electric throttle control device is in a condition incapable of controlling a throttle valve, thereby improving drivability. An ECU determines whether or not the electric throttle control device is in the condition incapable of controlling the throttle valve, and interrupts energization of the electric throttle control device when it is determined that the electric throttle control device is in the condition incapable of controlling the throttle valve. The throttle valve is held at a default opening position by a spring when the electric throttle control device is determined to be in the condition incapable of controlling the throttle valve. A throttle valve opening sensor detects a degree of opening of the throttle valve.

Abstract: There is provided a throttle control system and method for an internal combustion engine as well as an engine control unit, which are capable of controlling a throttle valve without any trouble even when the throttle valve is frozen. The throttle control system controls the degree of opening of the throttle valve. The opening of the throttle valve detected during control of the throttle valve to a fully-closed position at a start of the engine is set to a smallest angle. A temperature of the throttle valve is detected. A lower limit value of the target degree of opening is set to a degree of opening larger than the detected smallest angle of the throttle valve, when the detected smallest angle is larger than a predetermined degree of opening and at the same time the detected temperature of the throttle valve is lower than a predetermined temperature.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An abnormality detecting apparatus for an intake system of an internal combustion engine, which detects an abnormality of the intake system, is disclosed. The intake system has a throttle valve, a bypass passage bypassing the throttle valve, and an idling control valve for controlling the amount of air supplied through the bypass passage to the engine. A total intake air amount supplied to the engine is calculated. An amount of intake air supplied through the bypass passage is calculated based on a valve opening control quantity for the idling control valve. A parameter indicative of a leak air amount of the intake system is calculated according to the result of a comparison between the calculated total intake air amount and the amount of intake air supplied through the bypass passage.

Abstract: A highly stable engine failure diagnosing system free from influence of purging is presented. A monitoring apparatus for monitoring a fuel feed system of an internal combustion engine is provided with an A/F ratio detector and an A/F ratio controller for performing feedback control of the A/F ratio. An A/F ratio feedback coefficient is calculated according to the output of the detector. A malfunction determination parameter is calculated based on the coefficient. A purging is suspended when the parameter reaches a first decision value. The monitoring is suspended when the parameter reaches a second decision value in a purge cutting state. A value of the malfunction determination parameter it would take if the purge cut was not carried out is estimated using the value when the parameter reached the first decision value. The monitoring is resumed when the estimated value of the malfunction determination parameter reaches the second decision value.

Abstract: There are disclosed a fuel injection control system, a fuel injection control method, and an engine control unit for an internal combustion engine, which are capable of accurately controlling a fuel injection amount according to changes in a valve overlap period due to changes in a cam phase, thereby ensuring proper engine performance. The fuel injection control system for an internal combustion engine which is capable of changing a valve overlap period by changing a cam phase includes an ECU. The ECU calculates a cam phase difference between the present value and the immediately preceding value of the cam phase (amount of change in the valve overlap period), calculates a wall surface temperature of intake ports, and sets a basic fuel injection time period based on an intake pipe absolute pressure and an engine rotational speed.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A failure detection apparatus for a cooling system of an internal combustion engine is disclosed. The cooling system has a radiator, a cooling water pipe for circulating a cooling water in the engine to the radiator, and a thermostat provided in the cooling water pipe for opening and closing the cooling water pipe. An estimated cooling water temperature of the engine is calculated according to the engine operating condition. The estimated cooling water temperature is compared with a determination threshold set according to the detected vehicle speed at the time the detected cooling water temperature has exceeded a predetermined water temperature. If the estimated cooling water temperature is lower than or equal to the determination threshold, it is determined that the thermostat is normal.

Abstract: 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.