Abstract: A sealing valve 28 that controls a communication state between a fuel tank 10 and a canister 26 is provided. During stop of an internal combustion engine, the sealing valve 28 is generally closed, and the canister 26 is opened to the atmosphere. The sealing valve 28 is opened when the internal combustion engine is stopped, and differential pressure exceeding a valve opening determination value is generated between tank internal pressure and atmospheric pressure. A change in the tank internal pressure generated between before and after the sealing valve 28 is opened is detected. When the change in the tank internal pressure is below a predetermined determination value, closing failure of the sealing valve is determined.

Abstract: A sealing valve 28 that controls a communication state between a fuel tank 10 and a canister 26 is provided. During stop of an internal combustion engine, the sealing valve 28 is generally closed, and the canister 26 is opened to the atmosphere. The sealing valve 28 is opened when the internal combustion engine is stopped, and differential pressure exceeding a valve opening determination value is generated between tank internal pressure and atmospheric pressure. A change in the tank internal pressure generated between before and after the sealing valve 28 is opened is detected. When the change in the tank internal pressure is below a predetermined determination value, closing failure of the sealing valve is determined.

Abstract: A sealing valve 28 that controls a communication state between a fuel tank 10 and a canister 26 is provided. During stop of an internal combustion engine, the sealing valve 28 is generally closed, and the canister 26 is opened to the atmosphere. The sealing valve 28 is opened when the internal combustion engine is stopped, and differential pressure exceeding a valve opening determination value is generated between tank internal pressure and atmospheric pressure. A change in the tank internal pressure generated between before and after the sealing valve 28 is opened is detected. When the change in the tank internal pressure is below a predetermined determination value, closing failure of the sealing valve is determined.

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1-r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: A sealing valve is installed between a fuel tank and a canister. A purge VSV is installed between the canister and an intake path. A pump module unit is installed to introduce a negative pressure into the canister. The negative pressure is introduced into the canister while the purge VSV and sealing valve are closed. An open failure diagnostic check is conducted on the sealing valve in accordance with the prevalent canister side pressure. A close failure diagnostic check is conducted on the sealing valve by making use of a differential pressure that is generated across the sealing valve as a result of the open failure diagnostic check.

Abstract: A vapor passage 20 that makes communication between a fuel tank 10 and a canister 26 is provided. A purge passage 34 that makes communication between the canister 26 and an intake passage 38 of an internal combustion engine is provided. A sealing valve 28 that controls a communication state of the vapor passage 20 and a purge VSV 36 that controls a communication state of the purge passage 34 are provided. A tank internal pressure sensor 12 detects tank internal pressure Pt. The purge VSV 36 is controlled to purge evaporated fuel into the intake passage 38 during operation of the internal combustion engine. The sealing valve 28 is opened/closed depending on whether a predetermined purge is performed in an area where the tank internal pressure Pt is positive.

Abstract: An intake air oxygen concentration sensor calibration device is provided with an oxygen concentration sensor that detects a concentration of oxygen contained in intake air, intake passageway pressure detection means, stable condition determination means that determines whether the intake passageway pressure is in a stable condition based on the amplitude of fluctuations in intake passageway pressure and a predetermined stable condition criterion value, calibration coefficient calculation means that calculates a calibration coefficient based on the intake passageway pressure and a reference output value of the oxygen concentration sensor, and calibration means that calibrates the output of the oxygen concentration sensor based on the calibration coefficient, wherein and the stable condition criterion value is set so that the smaller the intake passageway pressure detected, the smaller the value, and the greater the intake passageway pressure detected, the greater the value, and the calibration coefficient calc

Abstract: Correction of a fuel injection amount in an internal combustion engine during purge of evaporative fuel is performed on the basis of an output from an intake-oxygen concentration sensor disposed in an intake passage of the internal combustion engine. If the amplitude of fluctuations in engine speed becomes equal to or greater than a predetermined value, it is determined that there is an anomaly in engine output. In addition, if an anomaly in engine output is detected during purge and if no anomaly in engine output is detected during stoppage of purge, an ECU determines that an anomaly has occurred in the intake-oxygen concentration sensor, cancels correction of the fuel injection amount based on an output from the intake-oxygen concentration sensor during purge, and corrects the fuel injection amount on the basis of outputs from exhaust-gas air-fuel ratio sensors.

Abstract: A vapor passage 20 that makes communication between a fuel tank 10 and a canister 26 is provided. A purge passage 34 that makes communication between the canister 26 and an intake passage 38 of an internal combustion engine is provided. A sealing valve 28 that controls a communication state of the vapor passage 20 and a purge VSV 36 that controls a communication state of the purge passage 34 are provided. A tank internal pressure sensor 12 detects tank internal pressure Pt. The purge VSV 36 is controlled to purge evaporated fuel into the intake passage 38 during operation of the internal combustion engine. The sealing valve 28 is opened/closed depending on whether a predetermined purge is performed in an area where the tank internal pressure Pt is positive.

Abstract: A sealing valve is installed between a fuel tank and a canister. A purge VSV is installed between the canister and an intake path. A pump module unit is installed to introduce a negative pressure into the canister. The negative pressure is introduced into the canister while the purge VSV and sealing valve are closed. An open failure diagnostic check is conducted on the sealing valve in accordance with the prevalent canister side pressure. A close failure diagnostic check is conducted on the sealing valve by making use of a differential pressure that is generated across the sealing valve as a result of the open failure diagnostic check.

Abstract: A sealing valve 28 that controls a communication state between a fuel tank 10 and a canister 26 is provided. During stop of an internal combustion engine, the sealing valve 28 is generally closed, and the canister 26 is opened to the atmosphere. The sealing valve 28 is opened when the internal combustion engine is stopped, and differential pressure exceeding a valve opening determination value is generated between tank internal pressure and atmospheric pressure. A change in the tank internal pressure generated between before and after the sealing valve 28 is opened is detected. When the change in the tank internal pressure is below a predetermined determination value, closing failure of the sealing valve is determined.

Abstract: Disclosed is an evaporated fuel treatment device that includes a sealing valve installed between a fuel tank and a canister, a pump module pressure sensor for detecting the pressure on the canister side pressure, and a tank internal pressure sensor for detecting a tank internal pressure. Upon detection of a significant difference between the canister side pressure and tank internal pressure, the device concludes that no open failure exists in the sealing valve.

Abstract: An intake air oxygen concentration sensor calibration device is provided with an oxygen concentration sensor that detects a concentration of oxygen contained in intake air, intake passageway pressure detection means, stable condition determination means that determines whether the intake passageway pressure is in a stable condition based on the amplitude of fluctuations in intake passageway pressure and a predetermined stable condition criterion value, calibration coefficient calculation means that calculates a calibration coefficient based on the intake passageway pressure and a reference output value of the oxygen concentration sensor, and calibration means that calibrates the output of the oxygen concentration sensor based on the calibration coefficient, wherein and the stable condition criterion value is set so that the smaller the intake passageway pressure detected, the smaller the value, and the greater the intake passageway pressure detected, the greater the value, and the calibration coefficient calc

Abstract: An intake air oxygen concentration sensor calibration device is provided with an oxygen concentration sensor that detects a concentration of oxygen contained in intake air, intake passageway pressure detection means, stable condition determination means that determines whether the intake passageway pressure is in a stable condition based on the amplitude of fluctuations in intake passageway pressure and a predetermined stable condition criterion value, calibration coefficient calculation means that calculates a calibration coefficient based on the intake passageway pressure and a reference output value of the oxygen concentration sensor, and calibration means that calibrates the output of the oxygen concentration sensor based on the calibration coefficient, wherein and the stable condition criterion value is set so that the smaller the intake passageway pressure detected, the smaller the value, and the greater the intake passageway pressure detected, the greater the value, and the calibration coefficient calc

Abstract: Correction of a fuel injection amount in an internal combustion engine during purge of evaporative fuel is performed on the basis of an output from an intake-oxygen concentration sensor disposed in an intake passage of the internal combustion engine. If the amplitude of fluctuations in engine speed becomes equal to or greater than a predetermined value, it is determined that there is an anomaly in engine output. In addition, if an anomaly in engine output is detected during purge and if no anomaly in engine output is detected during stoppage of purge, an ECU determines that an anomaly has occurred in the intake-oxygen concentration sensor, cancels correction of the fuel injection amount based on an output from the intake-oxygen concentration sensor during purge, and corrects the fuel injection amount on the basis of outputs from exhaust-gas air-fuel ratio sensors.

Abstract: Fuel vapor is introduced into an intake passage of a direct fuel injection type engine by a fuel vapor purge apparatus. The intake passage is provided with an intake oxygen concentration sensor for detecting the amount of fuel vapor in intake air. An ECU corrects the amount of fuel injection from each direct fuel injection valve in accordance with the amount of fuel vapor detected, and changes the fuel injection starting timing and the fuel injection ending timing in accordance with the amount of fuel vapor.

Abstract: Fuel vapor is introduced into an intake passage of a direct fuel injection type engine by a fuel vapor purge apparatus. The intake passage is provided with an intake oxygen concentration sensor for detecting the amount of fuel vapor in intake air. An ECU corrects the amount of fuel injection from each direct fuel injection valve in accordance with the amount of fuel vapor detected, and changes the fuel injection starting timing and the fuel injection ending timing in accordance with the amount of fuel vapor.

Abstract: An intake air oxygen concentration sensor calibration device is provided with an oxygen concentration sensor that detects a concentration of oxygen contained in intake air, intake passageway pressure detection means, stable condition determination means that determines whether the intake passageway pressure is in a stable condition based on the amplitude of fluctuations in intake passageway pressure and a predetermined stable condition criterion value, calibration coefficient calculation means that calculates a calibration coefficient based on the intake passageway pressure and a reference output value of the oxygen concentration sensor, and calibration means that calibrates the output of the oxygen concentration sensor based on the calibration coefficient, wherein and the stable condition criterion value is set so that the smaller the intake passageway pressure detected, the smaller the value, and the greater the intake passageway pressure detected, the greater the value, and the calibration coefficient calc