An aftertreatment system comprises a SCR system, an engine out NOx (EONOx) adjustment system and a controller. The controller is configured to instruct the EONOx adjustment system to adjust an EONOx amount between a high EONOx level for a first predetermined time and a low EONOx level for a second predetermined time when the SCR system is in a diagnostic enabling condition. The controller determines a SCR system out NOx (SONOx) amount. The controller determines an efficiency parameter of the SCR system from the SONOx amount when the EONOx amount transitions from the low EONOx level to the high EONOx level and if the efficiency parameter satisfies a predetermined threshold. In response to the efficiency parameter not satisfying the predetermined threshold, the controller determines that the SCR system has failed.

A control device of an internal combustion engine comprises a heater control part configured to set a target temperature of the electrochemical cell and control the heater so that a temperature of the electrochemical cell becomes the target temperature. The heater control part sets the target temperature to a first temperature when water injection by the water injection device is not being demanded after a predetermined time elapses from startup of the internal combustion engine, and sets the target temperature to a second temperature when an operating state of the internal combustion engine is in a water outflow state where water injected by the water injection device reaches the exhaust passage without going through combustion of air-fuel mixture in the combustion chamber. The second temperature is higher than the first temperature.

Systems and apparatuses include an engine, an aftertreatment system including a catalyst, and a controller coupled to the aftertreatment system and the engine. During a warmup period for an engine, the controller determines a value regarding a mass flow rate of exhaust gas based on information received from at least one of the engine or the aftertreatment system. The controller receives a target value regarding the mass flow rate of the exhaust gas. The controller controls at least one of the engine, the aftertreatment system, or at least one component associated therewith to reach or attempt to reach the target value regarding the mass flow rate of the exhaust gas.

A system for determining a performance status of an exhaust aftertreatment system may include determining an ammonia-to-nitrogen ratio using a sample ammonia input value and a sample NO.sub.x input value. An actual NO.sub.x input value and an actual ammonia input value can be received. An emission value from may be received from a first sensor. A NO.sub.x emission estimate, an ammonia slip estimate, and an optimal ammonia storage value for a selective catalytic reduction may be determined using an iterative inefficiency calculation based, at least in part, on the actual NO.sub.x input value, the actual ammonia input value, and the ammonia-to-nitrogen ratio; and the NO.sub.x emission estimate, the ammonia slip estimate, and the optimal ammonia storage value may be outputted to a diagnostic system.

A particulate matter sensor detecting particulate matter in exhaust emissions is provided, which is resistant to having sensor surfaces buried by particulate matter residue. Detection electrodes are provided, with alternating polarity, laminated in a laminating direction, separated by insulation. Of the detection electrodes, first detection electrodes of one polarity and second detection electrodes of the other polarity are exposed perpendicular to the laminating direction. In the direction perpendicular to the laminating direction, the particulate matter sensor has target accumulating parts on which the particulate matter is accumulated. In the target accumulating parts, the thickness W1 of the first detection electrodes in the laminating direction is greater than the thickness W2 of the second detection electrodes in the laminating direction.

An exhaust gas sensor arrangement structure includes a catalyst which purifies exhaust gas of an engine; and exhaust gas sensors which detect an exhaust gas component of the engine; the catalyst is provided under the engine; and the exhaust gas sensors are provided within a width of the engine in a front/rear direction so that the catalyst is provided between the exhaust gas sensors at front and rear sides of the catalyst.

A method for diagnosing an exhaust component in an exhaust passage for an internal combustion engine of a vehicle. In the method, operating parameters of the internal combustion engine are monitored and recorded by a control unit while the internal combustion engine is running. If a predefined emission threshold for the exhaust component for compliance with emissions is found to have been exceeded, the current operating parameters of the internal combustion engine are stored in a control unit. The operating state of the internal combustion engine when the predefined emission threshold is exceeded is reproduced on a vehicle test bench using the stored operating parameters. The diagnosis of the exhaust component is carried out based on a comparison between the current measured value from the exhaust component and the current measured value from an emission measuring device and/or the predefined emission threshold.

An exhaust purification system comprising an exhaust purification catalyst, a downstream side air-fuel ratio sensor, and a control device performing air-fuel ratio control for controlling an air-fuel ratio of exhaust gas and abnormality diagnosis control for diagnosing the downstream side air-fuel ratio sensor. In the air-fuel ratio control, the control device alternately and repeatedly switches the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst between a rich air-fuel ratio and a lean air-fuel ratio. In the abnormality diagnosis control, the control device judges that the downstream side air-fuel ratio sensor has become abnormal when the air-fuel ratio of the exhaust gas is made the rich air-fuel ratio by the air-fuel control and the output air-fuel ratio of the downstream side air-fuel ratio sensor changes from an air-fuel ratio richer than a predetermined lean judged air-fuel ratio to an lean air-fuel ratio.

A particulate sensor can reduce the amount of floating ions discharged from the interior of a gas introduction pipe to the outside through a gas discharge opening, without providing an auxiliary electrode member which applies to the floating ions a repulsive force toward the gas introduction pipe to thereby assist the collection of the floating ions by the gas introduction pipe. The particulate sensor has an collection member which is connected to a gas introduction pipe to thereby be maintained at a collection potential and is disposed in the interior of the gas introduction pipe to be located between a forward end of the discharge electrode member and a gas discharge opening such that the forward end of the discharge electrode member cannot be visually recognized from the outside of the gas introduction pipe through the gas discharge opening.

A method of generating vehicle control data includes: storing, with a storage device, relationship prescription data; operating, with an execution device, an operable portion of an internal combustion engine; acquiring, with the execution device, a detection value from a sensor that detects the state of the vehicle; calculating, with the execution device, a reward; and updating, with the execution device, the relationship prescription data using update mapping determined in advance, the update mapping using the state of the vehicle based on the detection value, an operation amount used to operate the operable portion, and the reward corresponding to the operation as arguments, and returning the relationship prescription data which have been updated such that an expected profit for the reward calculated when the operable portion is operated in accordance with the relationship prescription data increases.