Abstract: An engine control apparatus includes a valve operating mechanism for transmitting the rotation of a crankshaft to camshafts through a timing wrapping member. A control unit includes a phase detection section that detects the phase of a camshaft relative to the crankshaft, an abnormality determination section that makes, based on the detected phase, a determination whether the valve operating mechanism is abnormal, a threshold storage section that stores determination references as a lower limit threshold and an upper limit threshold, an initial phase storage section that stores, as an initial phase, a phase detected at the time of engine installation, and a phase correction section that corrects the phase detected during engine operation by using the initial phase thereby to calculate a corrected phase. The abnormality determination section outputs an abnormality determination signal when the corrected phase deviates from a determination reference range of from the lower to upper limit thresholds.

Abstract: An engine control apparatus includes a valve operating mechanism for transmitting the rotation of a crankshaft to camshafts through a timing wrapping member. A control unit includes a phase detection section that detects the phase of a camshaft relative to the crankshaft, an abnormality determination section that makes, based on the detected phase, a determination whether the valve operating mechanism is abnormal, a threshold storage section that stores determination references as a lower limit threshold and an upper limit threshold, an initial phase storage section that stores, as an initial phase, a phase detected at the time of engine installation, and a phase correction section that corrects the phase detected during engine operation by using the initial phase thereby to calculate a corrected phase. The abnormality determination section outputs an abnormality determination signal when the corrected phase deviates from a determination reference range of from the lower to upper limit thresholds.

Abstract: Air-fuel ratio control apparatus for an engine of automobile for controlling an air-fuel ratio to a desired value includes module (33) for computing a purge ratio (Pr) from a purge quantity (QPRG) and an engine operation state, module (35) for computing a purge air concentration (Pn) from the purge ratio (Pr) and an air-fuel ratio feedback correcting coefficient (CFB), module (36) for computing a purge air concentration correcting coefficient (CPRG) from the purge ratio and the purge air concentration, module (39) for computing a fuel injection quantity (Qf) supplied to the engine (6) from the purge air concentration correcting coefficient, and module (37) for detecting an accelerating state of the automobile. The purge air concentration correcting coefficient is reset to an initial value when the purge air concentration correcting coefficient is not greater than a predetermined value (indicating leanness) and when the acceleration is detected.

Abstract: Air-fuel ratio control apparatus for an engine of automobile for controlling an air-fuel ratio to a desired value includes module (33) for computing a purge ratio (Pr) from a purge quantity (QPRG) and an engine operation state, module (35) for computing a purge air concentration (Pn) from the purge ratio (Pr) and an air-fuel ratio feedback correcting coefficient (CFB), module (36) for computing a purge air concentration correcting coefficient (CPRG) from the purge ratio and the purge air concentration, module (39) for computing a fuel injection quantity (Qf) supplied to the engine (6) from the purge air concentration correcting coefficient, and module (37) for detecting an accelerating state of the automobile. The purge air concentration correcting coefficient is reset to an initial value when the purge air concentration correcting coefficient is not greater than a predetermined value (indicating leanness) and when the acceleration is detected.

Abstract: An O2-sensor fault diagnosis apparatus and method therefor, which are capable of detecting wire breaking of an O2-sensor with reliability and successively performing fault diagnosis with minimal effect on an exhaust gas. An O2-sensor 19 detects concentration of oxygen contained in an exhaust gas of an engine 1. An ECU 20 controls a quantity of fuel supplied to the engine 1 through feedback control according to an output signal of the O2-sensor. A fault diagnosis portion changes an input resistance value of an input circuit that is connected to the O2-sensor 19 and constitutes the ECU 20 each time a control condition for determining that the O2-sensor 19 is in an inactive state is satisfied, determines that wire breaking occurs in the O2-sensor 19 only if the output voltage of the O2-sensor 19 exceeds a predetermined voltage, and activates an informing portion to send a notice showing that there is a fault in the O2-sensor 19.

Abstract: When operating area detecting device detects an operating area that has a predetermined rotation number of below, flame-cut determination selecting circuitry determines the flame-cut on the basis of the logical product between a detection result of first flame-cut detecting device and a detection result of second flame-cut detecting circuitry.

Abstract: To obtain a fault diagnostic apparatus of an evaporation purge system by which a fault detection of a purge vent valve can accurately be performed with no wrong judgment.

Abstract: When operating area detecting means detects an operating area that has a predetermined rotation number of below, flame-cut determination selecting means determines the flame-cut on the basis of the logical product between a detection result of first flame-cut detecting means and a detection result of second flame-cut detecting means.

Abstract: To obtain a fault diagnostic apparatus of an evaporation purge system by which a fault detection of a purge vent valve can accurately be performed with no wrong judgment.

Abstract: An O2-sensor fault diagnosis apparatus and method therefor, which are capable of detecting wire breaking of an O2-sensor with reliability and successively performing fault diagnosis with minimal effect on an exhaust gas. An O2-sensor 19 detects concentration of oxygen contained in an exhaust gas of an engine 1. An ECU 20 controls a quantity of fuel supplied to the engine 1 through feedback control according to an output signal of the O2-sensor. A fault diagnosis portion changes an input resistance value of an input circuit that is connected to the O2-sensor 19 and constitutes the ECU 20 each time a control condition for determining that the O2-sensor 19 is in an inactive state is satisfied, determines that wire breaking occurs in the O2-sensor 19 only if the output voltage of the O2-sensor 19 exceeds a predetermined voltage, and activates an informing portion to send a notice showing that there is a fault in the O2-sensor 19.

Abstract: A device for controlling the vehicle to travel at a constant speed, which clearly distinguishes a downhill road over a flat road while the vehicle is traveling at a constant speed, and resets or resumes the overdrive position in order to stably maintain a vehicle speed at all times. The device comprises a downhill control means 10 for resetting the overdrive position of an automatic transmission 2 when the vehicle is traveling a downhill, wherein the downhill control means includes a downhill state detection means 13 for detecting the downhill state of the vehicle based on the throttle opening degree &thgr; and the vehicle speed Vs, and an overdrive reset means 14 for resetting the overdrive position of the automatic transmission in response to the downhill state, wherein the reset state of the overdrive position is maintained while the downhill state is being detected, and the throttle valve opening degree is used as a reference for judging that the overdrive is resumed from the state of being shifted down.

Abstract: A device for controlling the amount of the air taken in by an engine, for improving the starting performance of when the accelerator pedal is depressed from the idling state. The device comprises a throttle control means 10A for operating a target throttle opening degree &thgr;o of a throttle valve 6 based on said throttle opening degree &thgr;, an accelerator opening degree &agr; and an idle signal D, and a throttle actuator 7 for opening and closing said throttle valve so that said throttle opening degree comes into agreement with said target throttle opening degree, wherein said throttle control means includes a means 11 for operating a first target throttle opening degree &thgr;o1 based on said accelerator opening degree, a means 12 for operating a second target throttle opening degree &thgr;o2 based on the idle signal, and a means 13 for operating a target throttle opening degree &thgr;o by adding up the first and second target throttle opening degrees together.