Systems and methods for determining fuel delay in a fuel injected engine with cylinders that may be deactivated are presented. In one example, the fuel injection delay is determined via a cylinder firing schedule array when the cylinder firing schedule array is available. The fuel injection delay is determined via weighted average of a fuel injection delay of a present engine cycle and a fuel injection delay of a past engine cycle when the cylinder firing schedule array is not available.

Methods and systems for enabling regeneration of a particulate filter of an engine system are provided. In one embodiment, a method includes: receiving, by a processor, a request for particulate filter regeneration; in response to the request, determining, by the processor, at least one of a compression ratio and an expansion ratio; generating, by the processor, control signals to actuators of the engine system to adjust the at least one of the compression ratio and the expansion ratio to achieve a desired exhaust temperature; generating, by the processor, control signals to actuators of the engine system to optimize torque output based on the desired exhaust temperature, engine speed, and a desired engine load; and initiating, by the processor, regeneration of the particulate filter based on the command signals.

A method for operating a drive device having a drive unit producing exhaust gas and an exhaust gas posttreatment device designed as a vehicle catalytic converter for posttreatment of the exhaust gas. A first measured value describing the residual oxygen content in the exhaust gas is measured by a first lambda sensor arranged upstream of the exhaust gas posttreatment device and a second measured value describing the residual oxygen content in the exhaust gas is measured by a second lambda sensor arranged downstream of the exhaust gas posttreatment device. The combustion air ratio of a fuel-air mixture used to operate the drive unit is set during an at least temporarily performed normal operating mode on the basis of the first measured value, the second measured value, and a threshold value for the second measured value.

An air-fuel ratio controller of an internal combustion engine includes an open-loop processor setting a base injection amount, a feedback processor calculating a feedback operation amount, an increase processor performing an increase correction on the base injection amount when a temperature of the internal combustion engine is a specified temperature or lower, an operation processor operating a fuel injection valve based on the corrected base injection amount and that is corrected using the feedback operation amount and a learning value, and an update processor updating the learning value. If the increase processor performs the increase correction, the update processor updates the learning value to increase an increase correction rate of the base injection amount when a temperature of the cylinder wall surface is high.

A diagnostic device incorporates a processor and a memory and diagnoses a failure related to a fuel injection system for an engine whose air-fuel ratio of is feedback-controlled. The diagnostic device includes a calculation unit which calculates a corrected value of a fuel injection amount according to a difference between a target value and a measured value of the air-fuel ratio. The diagnostic device includes a setting unit which sets a mask period in which a failure diagnosis is suspended, according to the corrected value upon switchover of a fuel injection mode. The diagnostic device includes a diagnostic unit which does not carry out the diagnosis in the mask period and carries out the diagnosis outside the mask period.

An air-fuel ratio control controls an air-fuel ratio (air-fuel ratio of an engine) of a mixture supplied to the engine, based on an output value of the downstream-side air-fuel ratio sensor disposed downstream of a catalyst. That is, the air-fuel ratio control apparatus sets the air-fuel ratio of the engine at a rich air-fuel ratio when the output Voxs is smaller than a reference value VREF (when a rich request is occurring). The air-fuel ratio control apparatus sets the air-fuel ratio of the engine at a lean air-fuel ratio when the output Voxs is larger than a reference value VREF (when a lean request is occurring). The air-fuel ratio control apparatus makes the target value VREF gradually come closer to a reference value VF (stoichiometric air-fuel ratio corresponding value) from a certain value, when the output value Voxs deviates greatly from the reference value Vf (points P1-P3).

An electronic control method for a throttle by an electronic control throttle device that controls the throttle while an electronic control unit generates a control signal based on an input data signal. The method may include calculating an engine rotation speed deviation from a difference between an engine rotation speed and an input engine rotation speed command, calculating an engine rotational acceleration based on the engine rotation speed, obtaining a proportional torque from a product of the engine rotation speed deviation and a predetermined coefficient, obtaining an integral torque by integrating a value obtained by subtracting a product of the engine rotational acceleration and the predetermined coefficient from the product of the engine rotation speed deviation and the predetermined coefficient, and generating a control signal for the throttle by using a sum of the proportional torque and the integral torque as a value of a torque command.

An electronic control method for a throttle by an electronic control throttle device that controls the throttle while an electronic control unit generates a control signal based on an input data signal. The method may include calculating an engine rotation speed deviation from a difference between an engine rotation speed and an input engine rotation speed command, calculating an engine rotational acceleration based on the engine rotation speed, obtaining a proportional torque from a product of the engine rotation speed deviation and a predetermined coefficient, obtaining an integral torque by integrating a value obtained by subtracting a product of the engine rotational acceleration and the predetermined coefficient from the product of the engine rotation speed deviation and the predetermined coefficient, and generating a control signal for the throttle by using a sum of the proportional torque and the integral torque as a value of a torque command.

A vehicle includes an engine and an engine start controller. The engine start controller is configured to derive an integrated value while a target driving force derived on a basis of an accelerator operation amount is larger than or equal to a predetermined first threshold value from a time point when the target driving force becomes larger than or equal to the first threshold value, and to start the engine when the integrated value becomes larger than or equal to a predetermined second threshold value. The integrated value is obtained by integrating a difference value between the target driving force and the first threshold value.

Methods and systems are provided for an exhaust system. In one example, a method may include determining presence of a zone flow based on a comparison of a first exhaust sensor and a second exhaust sensor. The presence or absence of the zone flow may determine a rate at which an air-fuel ratio is adjusted.