A CPU stops combustion control of Cylinder #1 in order to perform a regeneration process of a GPF and performs a regeneration process of causing an air-fuel ratio of an air-fuel mixture in Cylinders #2 to #4 to be richer. When it is determined that a misfire has occurred because a misfire rate when the regeneration process is not being performed is equal to or greater than a predetermined value, the CPU determines that an internal combustion engine has returned to a normal state based on the premise that the misfire rate when the regeneration process is not being performed decreases.

Provided is a control device configured to be able to execute, in an engine which includes a DOC, a DPF, and a temperature increase unit including an exhaust throttle valve, for increasing a temperature of each of the DOC and the DPF, a forced regeneration process of removing PM deposited on the DPF by increasing the temperature of the DPF. The control device includes a flow rate estimation part configured to estimate an intake flow rate of a combustion gas sent into a cylinder of the engine. The flow rate estimation part is configured to estimate a first intake flow rate, which is the intake flow rate in the forced regeneration process, from an opening degree of the exhaust throttle valve and a first state amount which indicates an operation state of the engine including a rotation speed of the engine, based on a first relationship representing a relationship between the first intake flow rate, and the opening degree of the exhaust throttle valve and the first state amount, in the forced regeneration process.

A controller is configured to perform a process of obtaining an exhaust pressure upstream of a filter inside an exhaust passage and an intake air amount detected by an air flowmeter, when the filter in which a deposition amount of particulate matter is a specified amount is referred to as a reference filter, a calculation process of calculating an exhaust pressure rate that indicates a ratio of the obtained exhaust pressure to an exhaust pressure at the reference filter for the obtained intake air amount, and a setting process of setting the exhaust pressure rate that is maintained at a specific value during engine operation.

A method is disclosed for controlling an engine assembly comprising an internal combustion engine and an exhaust gas treatment apparatus. The aftertreatment assembly may require cleaning from time to time, and where this involves active thermal management of the aftertreatment assembly, the method involves performing the following steps: (a) imposing a first limit on engine speed; (b) awaiting an engine safe state; and (c) implementing a cleaning process comprising: (i) injecting fuel into the engine such that the fuel passes through the engine without combusting for the fuel to combust in the diesel oxidation catalyst so as to target an increase in exhaust gas temperature in the diesel oxidation catalyst; and (ii) removing the first limit on engine speed and targeting an engine speed set point, wherein the engine speed set point is at a higher speed than the first limit on engine speed.

A method includes: initiating a low engine-out NOx (LEON) mode by controlling a component of a vehicle having an aftertreatment system to decrease an instantaneous engine-out NOx (EONOx) amount; comparing a temperature of the aftertreatment system during the LEON mode to a warm-operation threshold temperature; responsive to determining that the temperature of the aftertreatment system exceeds the warm-operation threshold temperature, disengaging the LEON mode; responsive to determining that the temperature of the aftertreatment system is below the warm-up operation threshold temperature, comparing information indicative of an operating status of the vehicle to a LEON exit threshold; and disengaging the LEON mode responsive to determining that the information indicative of the operating status of the vehicle during the LEON mode exceeds the LEON exit threshold.

A controller executes a first suspending process or a second suspending process when a vehicle satisfies a predetermined first condition or a predetermined second condition. The controller executes an integration process that, during execution of the first suspending process or the second suspending process, obtains an integrated value of an intake air amount of the internal combustion engine from when the first suspending process or the second suspending process that is being executed was started. When the integrated value is greater than or equal to a threshold, the controller stops the first suspending process or the second suspending process that is being executed. When the amount of particular matter deposited in a filter is the same, a first threshold, which is the threshold for the first suspending process, is greater than a second threshold, which is the threshold for the second suspending process.

A control system is provided for a diesel particulate filter (DPF) system of a diesel engine configured for operation in an off-highway vehicle. The control system includes a controller configured to receive a signal corresponding to a fill state of the DPF being at or above a first threshold. The controller is configured to selectively induce a parasitic load on the diesel engine to increase an operating temperature of the engine in response to receiving the signal.

A controller for a hybrid electric vehicle including an internal combustion engine is provided. The internal combustion engine includes a filter arranged in an exhaust passage collect particulate matter from exhaust gas. The controller executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process uses a fuel cutoff process when deceleration of the hybrid electric vehicle is required. The second deceleration control process does not use the fuel cutoff process when deceleration of the hybrid electric vehicle is required. The selection process selects execution of the second deceleration control process when a PM deposition amount is greater than or equal to a threshold value and selects execution of the first deceleration control process when the PM deposition amount is less than the threshold value.

A controller for a hybrid electric vehicle including an internal combustion engine is provided. The internal combustion engine includes a filter arranged in an exhaust passage collect particulate matter from exhaust gas. The controller executes a first deceleration control process, a second deceleration control process, and a selection process. The first deceleration control process uses a fuel cutoff process when deceleration of the hybrid electric vehicle is required. The second deceleration control process does not use the fuel cutoff process when deceleration of the hybrid electric vehicle is required. The selection process selects execution of the second deceleration control process when a PM deposition amount is greater than or equal to a threshold value and selects execution of the first deceleration control process when the PM deposition amount is less than the threshold value.

A control apparatus for an internal combustion engine performs a first acquisition process for acquiring a first index value corresponding to an integrated amount of intake air during a performance of the fuel cutoff process, and a cancellation process for cancelling the fuel cutoff process when the first index value becomes equal to or larger than a first predetermined value during the performance of the fuel cutoff process. Besides, the control apparatus performs a second acquisition process for acquiring a second index value corresponding to an elapsed time from the end of the fuel cutoff process to the subsequent start of the fuel cutoff process, and a change process for making the first predetermined value smaller when the second index value is small in starting the fuel cutoff process than when the second index value is large in starting the fuel cutoff process.