A system and method for detecting and mitigating automatic ignition in a cylinder of an internal combustion engine. The method includes providing a first sensor for sensing and determining a crank angle of a crankshaft of the engine. A second sensor is provided for detecting a change in an engine vibration frequency caused by Auto Ignition (AI). The engine vibration signal of the second sensor is processed into a knock intensity signal. The knock intensity signal is indicative of the cylinder pressure and is acquired when the crank angle is between a first predetermined crank angle and a second predetermined crank angle. At least one characteristic of the knock intensity signal is determined and the at least one characteristic of the knock intensity signal is compared to at least one predetermined characteristic threshold. If the at least one characteristic of the knock intensity signal is determined to exceed the at least one predetermined characteristic threshold, then at least one auto ignition mitigating action is performed to mitigate the auto ignition event.

A method for controlling the speed of an internal combustion engine and a speed control circuit for carrying out the method. For controlling, fuel energy is used as an output variable. The control units are calculated in accordance with a stationary proportion gain which is calculated proportionally to the fuel energy and inversely proportional to the engine speed.

An internal combustion engine system includes: an in-cylinder pressure sensor; a crank angle sensor; and a seal portion that seals a space between an outer face of a housing and a wall surface of a cylinder head. A slope that is a ratio of the amount of decrease in a heat release amount relative to the amount of increase in a crank angle is calculated in a period during an expansion stroke from a combustion end point until an opening timing of an exhaust valve. The existence or nonexistence of an abnormality in the sealing function of the seal portion is determined based on whether or not a ratio of the amount of decrease in the slope to the amount of increase in an engine speed is greater than a threshold value.

A method for operating an internal combustion engine comprises providing a vehicle having an internal combustion gasoline engine including multiple cylinders and wherein the engine is operating in a deactivated cylinder mode, receiving a torque request if a cylinder reactivation torque smoothing mode is active, setting a variable torque ratio to 1.0 if the torque request is greater than a fast exit threshold torque, setting the variable torque ratio to 0.0 if the torque request is less than a slow exit threshold torque, setting the variable torque ratio to a value between 0.0 and 1.0 if the torque request is between the fast exit threshold torque and slow exit threshold torque, and calculating a component of final engine output torque.

A system includes one or more processors configured to be operably coupled to a vehicle system configured to travel along a route during a trip. The vehicle system has a vehicle particulate filter (VPF) disposed within an exhaust passage of the vehicle system. The one or more processors are configured to determine, based on trip information about the trip of the vehicle system, one or more regeneration-incompatible (RI) portions of the trip. The RI portions are associated with operating conditions of the vehicle system that are unsuitable for contemporaneous active regeneration of the VPF. The one or more processors are further configured to schedule an active regeneration (AR) event for the vehicle system based on the one or more RI portions of the trip. The AR event occurs during a regeneration portion of the trip.

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 are provided for controlling a vehicle engine to deliver desired torque to a power take off device coupled to the engine. In one example, the method may include, learning a filtered PTO torque demand during vehicle acceleration, and steady state operation, and during transition in engine states using the learned PTO torque demand to adjust engine speed in order to deliver a desired engine torque output for optimal operation of the PTO device.

A control system in a vehicle includes a sensor and a control module. The sensor is programmed to detect an impact to the vehicle while the vehicle is in a key-off state and output an impact signal in response to detecting the impact. The control module is programmed to activate in response to the impact signal, receive a condition signal identifying a vehicle condition, and prevent at least one vehicle operation based at least in part on the condition signal.

Methods and systems are provided for reducing a spark plug soot load and a combustion chamber soot load by controlling spark plug timing while injecting water or washer fluid. In one example, water or washer fluid is injected during a torque reduction while advancing spark timing so as to provide at least a portion of the torque reduction while opportunistically cleaning soot from the spark plug and combustion chamber. By reducing spark plug soot load, misfire occurrence is reduced, while pre-ignition occurrence is reduced by decarbonizing the combustion chamber.

A wheelie suppressing device comprises a wheelie determiner section which detects a wheelie state; and a wheelie suppressing section which performs a wheelie suppressing control for suppressing an engine output when the wheelie determiner section has detected the wheelie state, wherein the wheelie suppressing control includes a first suppressing control for suppressing the engine output while performing fuel feeding and an ignition operation, and a second suppressing control for suppressing the engine output by performing the fuel feeding or the ignition operation at a reduced rate.