Abstract: A fault diagnosis device for a fluid feed system comprises a first acquiring part acquiring values as a fluid pressure and pump rotational speed before fluid injection, a second acquiring part acquiring values as a fluid pressure and pump rotational speed during fluid injection, a pump rotational speed difference calculating part calculating a pump rotational speed difference comprising a difference between a pump rotational speed during fluid injection and a pump rotational speed before fluid injection when the fluid pressure before fluid injection and the fluid pressure during fluid injection match, and an abnormality judging part judging if an abnormality has occurred in a flow rate of fluid injected from an injection device based on the pump rotational speed difference.

Abstract: In the abnormality diagnosis device which carries out an abnormality diagnosis of the reducing agent adding device by obtaining a diagnostic parameter which is a parameter correlated with an amount of pressure drop in a reducing agent passage in the case where, from a state in which an addition valve has been closed and in which a voltage to be applied to a pump is controlled to a diagnostic voltage so that the pressure in the reducing agent passage becomes a predetermined pressure, the addition valve is made to open in a state where the voltage to be applied to the pump is maintained at the diagnostic voltage, and by making a comparison between the diagnostic parameter and a predetermined threshold value, the abnormality diagnosis is carried out by using the diagnostic parameter or the predetermined threshold value which is corrected based on the pump discharge capacity of the pump.

Abstract: In the abnormality diagnosis device which carries out an abnormality diagnosis of the reducing agent adding device by obtaining a diagnostic parameter which is a parameter correlated with an amount of pressure drop in a reducing agent passage in the case where, from a state in which an addition valve has been closed and in which a voltage to be applied to a pump is controlled to a diagnostic voltage so that the pressure in the reducing agent passage becomes a predetermined pressure, the addition valve is made to open in a state where the voltage to be applied to the pump is maintained at the diagnostic voltage, and by making a comparison between the diagnostic parameter and a predetermined threshold value, the abnormality diagnosis is carried out by using the diagnostic parameter or the predetermined threshold value which is corrected based on the pump discharge capacity of the pump.

Abstract: A failure detection apparatus for a gas sensor includes an electronic control unit configured to: perform control so that a predetermined voltage, which is a positive voltage and is a voltage lower than a limiting current range when the gas sensor does not fail, is applied between a pair of electrodes; acquire a determination current, which is a current flowing between the pair of electrodes when the predetermined voltage is applied between the pair of electrodes; and determine whether the gas sensor fails based on the acquired determination current.

Abstract: A fault diagnosis device for a fluid feed system comprises a first acquiring part acquiring values as a fluid pressure and pump rotational speed before fluid injection, a second acquiring part acquiring values as a fluid pressure and pump rotational speed during fluid injection, a pump rotational speed difference calculating part calculating a pump rotational speed difference comprising a difference between a pump rotational speed during fluid injection and a pump rotational speed before fluid injection when the fluid pressure before fluid injection and the fluid pressure during fluid injection match, and an abnormality judging part judging if an abnormality has occurred in a flow rate of fluid injected from an injection device based on the pump rotational speed difference.

Abstract: An object of the disclosure is to provide a technology that enables abnormality diagnosis of an NOx trap catalyst to make the diagnosis that the NOx trap catalyst is abnormal even if the degree of deterioration of the NOx trap catalyst is relatively small yet. When performing abnormality diagnosis of an NOx trap catalyst, a system according to the disclosure performs a lean temperature raising process, which is the process of raising the temperature of the NOx trap catalyst to or above a predetermined temperature while keeping the air-fuel ratio of the exhaust gas flowing into the NOx trap catalyst at a lean air-fuel ratio. The system diagnoses abnormality of the NOx trap catalyst on the basis of the NOx storage efficiency of the NOx trap catalyst or a parameter correlating with that NOx storage efficiency after the completion of the lean temperature raise process.

Abstract: There is provided a technology pertaining to abnormality diagnosis of an NSR catalyst that enables the diagnosis that the NSR catalyst is abnormal to be made even when the degree of deterioration of the NSR catalyst is relatively small yet. An abnormality diagnosis apparatus is applied to an exhaust gas purification apparatus having an NSR catalyst and a fuel addition valve. The abnormality diagnosis apparatus includes a controller configured to perform a specific fuel addition process and diagnose the NSR catalyst. The controller starts the specific fuel addition process when the NSR catalyst is in a specific start condition, and diagnoses the NSR catalyst on the basis of the quantity of NOx flowing out of the NSR catalyst over a specific period in the period from when the specific fuel addition process is started to when the temperature of the NSR catalyst reaches the thermal desorption temperature.

Abstract: An object is to prevent a wrong diagnosis from being made in an abnormality diagnosis apparatus for an exhaust gas purification system including a filter and a PM sensor. After sensor regeneration is performed, the application of voltage to the PM sensor is started, and thereafter abnormality diagnosis of the PM sensor is performed based on whether or not a signal is output from the PM sensor. Abnormality diagnosis of the filter is performed based on whether or not the output value of the PM sensor reaches a predetermined abnormality criterion value. If the output value of the PM sensor reaches the predetermined abnormality criterion value before a predetermined diagnosis completion time after the abnormality diagnosis of the PM sensor, the filter is diagnosed as abnormal, and the application of voltage to the PM sensor is stopped at that time.

Abstract: In the abnormality diagnosis device which carries out an abnormality diagnosis of the reducing agent adding device by obtaining a diagnostic parameter which is a parameter correlated with an amount of pressure drop in a reducing agent passage in the case where, from a state in which an addition valve has been closed and in which a voltage to be applied to a pump is controlled to a diagnostic voltage so that the pressure in the reducing agent passage becomes a predetermined pressure, the addition valve is made to open in a state where the voltage to be applied to the pump is maintained at the diagnostic voltage, and by making a comparison between the diagnostic parameter and a predetermined threshold value, the abnormality diagnosis is carried out by using the diagnostic parameter or the predetermined threshold value which is corrected based on the pump discharge capacity of the pump.

Abstract: A function diagnostic system for a filter of an internal combustion engine may be provided. The function diagnostic system may include a PM sensor and an electronic control unit. The electronic control unit may be configured to: calculate a NOx conversion rate in the filter; determine whether a NOx converting function of the filter is normal; execute a sensor regeneration process for removing the PM deposited between an electrodes of the PM sensor; continuously monitor an output value of the PM sensor after a predetermined PM deposition restart time, after execution of the sensor regeneration process is finished; and determine that there is an abnormality in a PM trapping function of the filter, when the output vale of the PM sensor, which has been continuously monitored, is reduced when the electronic control unit determines that the NOx converting function of the filter is in a normal status.

Abstract: In a failure diagnosis apparatus that carries out standard diagnosis processing in which a failure of the particulate filter is diagnosed by making a comparison between an output value of the PM sensor at the time when a predetermined period of time has passed from a point in time at which sensor regeneration processing for removing the particulate matter deposited on an insulation layer of the PM sensor has ended, and a predetermined threshold value, the standard diagnosis processing is carried out in the case where rich spike processing according to the in-cylinder rich control is not carried out during the predetermined period of time, whereas the rich spike processing according to the in-cylinder rich control is carried out during the predetermined period of time, the standard diagnosis processing is not carried out.

Abstract: Embodiments of the present disclosure may improve the accuracy of abnormality diagnosis of a particulate filter using the output value of a particulate matter (PM) sensor provided in an exhaust passage. A time when deposition of PM between electrodes of the PM sensor is restarted after completion of a sensor recovery process may be specified as a PM deposition restart time. A process of diagnosing an abnormality of a filter based on the output value of the PM sensor at a first determination time after the PM deposition restart time may be specified as a filter diagnosis process. To determine, whether the filter diagnosis process is to be performed, a change rate of the output value of the PM sensor in a time period from the PM deposition restart time to a predetermined second determination time before the first determination time, may be compared with a threshold value.

Abstract: The invention provides a technique for more accurately executing failure diagnosis for an exhaust gas control apparatus having both a selective reduction function and a filter function. To this end, a failure diagnosis apparatus according to the invention for the exhaust gas control apparatus having both the selective reduction function and the filter function computes a NOx purification rate pertaining to a case where the exhaust gas control apparatus is normal based on an estimated value of the amount of particulate matter (PM) collected or accumulated in the exhaust gas control apparatus and an estimated value of the NO2 ratio of exhaust gas flowing into the exhaust gas control apparatus, and determines that the exhaust gas control apparatus fails when the difference between the result of the calculation and an actual NOx purification rate exceeds a threshold.

Abstract: An object of the disclosure is to provide a technology that enables abnormality diagnosis of an NOx trap catalyst to make the diagnosis that the NOx trap catalyst is abnormal even if the degree of deterioration of the NOx trap catalyst, is relatively small yet. When performing abnormality diagnosis of an NOx trap catalyst, a system according to the disclosure performs a lean temperature raising process, which is the process of raising the temperature of the NOx trap catalyst to or above a predetermined temperature while keeping the air-fuel ratio of the exhaust gas flowing into the NOx trap catalyst at a lean air-fuel ratio. The system diagnoses abnormality of the NOx trap catalyst on the basis of the NOx storage efficiency of the NOx trap catalyst or a parameter correlating with that NOx storage efficiency after the completion of the lean temperature raise process.

Abstract: A filter abnormality determination system includes: a PM sensor configured to introduce a part of exhaust gas flowing in the exhaust gas passage on the downstream side of a filter into a sensor body and to correlate a sensor output with an amount of particulate matter accumulated on a sensor element in the sensor body; an abnormality determining unit configured to perform filter abnormality determination on the basis of the output of the PM sensor; a determination timing determining unit configured to determine a timing at which the abnormality determining unit performs the abnormality determination on the basis of an estimated amount of particulate matter accumulated on the sensor element; and a determination performing adjusting unit configured to adjust the performing timing determined by the determination timing determining unit depending on a variation of an exhaust gas flow rate per unit time in the exhaust gas passage in which the PM sensor is disposed.

Abstract: There is provided a technology pertaining to abnormality diagnosis of an NSR catalyst that enables the diagnosis that the NSR catalyst is abnormal to be made even when the degree of deterioration of the NSR catalyst is relatively small yet. An abnormality diagnosis apparatus is applied to an exhaust gas purification apparatus having an NSR catalyst and a fuel addition valve. The abnormality diagnosis apparatus includes a controller configured to perform a specific fuel addition process and diagnose the NSR catalyst. The controller starts the specific fuel addition process when the NSR catalyst is in a specific start condition, and diagnoses the NSR catalyst on the basis of the quantity of NOx flowing out of the NSR catalyst over a specific period in the period from when the specific fuel addition process is started to when the temperature of the NSR catalyst reaches the thermal desorption temperature.

Abstract: Embodiments of the present disclosure improve the accuracy of abnormality diagnosis of a particulate filter using the output value of a PM sensor provided downstream of the particulate filter in an exhaust passage. A configuration of the invention compares a change rate of an output value of the PM sensor prior to execution of a filter diagnosis process of diagnosing an abnormality of the filter based on the output value of the PM sensor, with a reference value and determines whether a filter abnormality process is to be performed. A higher value is set to the reference value, which is to be compared with the change rate of the output value of the PM sensor, in the case where the deposition amount of PM between electrodes of the PM sensor is expected to be large, compared with the case where the deposition amount of PM is expected to be small.

Abstract: An object is to prevent a wrong diagnosis from being made in an abnormality diagnosis apparatus for an exhaust gas purification system including a filter and a PM sensor. After sensor regeneration is performed, the application of voltage to the PM sensor is started, and thereafter abnormality diagnosis of the PM sensor is performed based on whether or not a signal is output from the PM sensor. Abnormality diagnosis of the filter is performed based on whether or not the output value of the PM sensor reaches a predetermined abnormality criterion value. If the output value of the PM sensor reaches the predetermined abnormality criterion value before a predetermined diagnosis completion time after the abnormality diagnosis of the PM sensor, the filter is diagnosed as abnormal, and the application of voltage to the PM sensor is stopped at that time.

Abstract: In a failure diagnosis device of an emission control system that utilizes an electrode-based PM sensor to diagnose a failure of a particulate filter, some embodiments may be to suppress reduction of accuracy of diagnosis of a failure due to in-cylinder rich control. The failure diagnosis device of the emission control system performs a measurement process. The measurement process includes a sensor recovery process of removing PM depositing between the electrodes of the electrode-based PM sensor, a process of starting application of the predetermined voltage to the electrodes of the PM sensor after completion of the sensor recovery process, and a process of obtaining an output value of the PM sensor after elapse of a predetermined time period since the start of application of the predetermined voltage to the electrodes of the PM sensor.

Abstract: In a failure diagnosis apparatus that carries out standard diagnosis processing in which a failure of the particulate filter is diagnosed by making a comparison between an output value of the PM sensor at the time when a predetermined period of time has passed from a point in time at which sensor regeneration processing for removing the particulate matter deposited on an insulation layer of the PM sensor has ended, and a predetermined threshold value, the standard diagnosis processing is carried out in the case where rich spike processing according to the in-cylinder rich control is not carried out during the predetermined period of time, whereas the rich spike processing according to the in-cylinder rich control is carried out during the predetermined period of time, the standard diagnosis processing is not carried out.