A control system includes a controller. The controller acquires a crank counter value each time a fixed time elapses. The controller calculates the number of the crank counter values corresponding to the top dead center of the plunger between a previously acquired crank counter value and a currently acquired crank counter value with reference to the map each time the crank counter value is acquired and calculate the number of driving times of the high pressure fuel pump by integrating the calculated number.

A control system includes a controller. The controller counts the number of driving times of the high pressure fuel pump, which is the number of the reciprocating motions of the plunger based on a crank counter that is counted up at every predetermined crank angle. The controller stores a map in which a top dead center of the plunger is associated with a crank counter value, and store a crank counter value while an engine is stopped as a stop-time counter value. The controller calculates, referring to the map, the number of the crank counter values corresponding to the top dead center of the plunger between a crank counter value and the stop-time counter value, and set a calculated number as the number of driving times.

A control system includes a controller. The controller counts the number of driving times of the high pressure fuel pump, which is the number of the reciprocating motions of the plunger based on a crank counter that is counted up at every predetermined crank angle. The controller stores a map in which a top dead center of the plunger is associated with a crank counter value, and store a crank counter value while an engine is stopped as a stop-time counter value. The controller calculates, referring to the map, the number of the crank counter values corresponding to the top dead center of the plunger between a crank counter value and the stop-time counter value, and set a calculated number as the number of driving times.

A compression-release engine brake system for effectuating a compression-release engine braking operation of an internal combustion engine. The compression-release system includes a lost motion exhaust rocker assembly including an exhaust rocker arm, an actuation device including an actuation piston and an actuation cavity, and a reset device including a reset check valve and a slider-piston. Hydraulic fluid in the exhaust rocker arm is locked in the actuation cavity when the reset check valve is in the closed position, and flows through the reset check valve when the reset check valve is in the open position. The slider-piston is associated with the reset check valve so that in an extended position of the slider-piston the reset check valve is free to move toward the closed position, and in a retracted position of the slider-piston the reset check valve is moved to the open position thereof by the slider-piston.

Systems and methods for operating a spark ignition engine that includes a particulate filter in the engine's exhaust system are described. In one example, a threshold temperature at which the spark ignition engine may be automatically stopped is adjusted according to an amount of soot that is stored in the particulate filter.

Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations, while the fluid level in the standpipe is estimated based on echo times of an ultrasonic signal transmitted by a sensor positioned in a recess at the bottom of the vertical standpipe. Engine power is limited differently based on distinct coolant level states determined based on a change in level of coolant in the reservoir over a duration.

Methods and systems are providing for improving engine coolant level estimation to reduce engine overheating. The level of fluid in a coolant overflow reservoir is inferred based on the fluid level in a hollow vertical standpipe fluidically coupled to the reservoir at top and bottom locations, while the fluid level in the standpipe is estimated based on echo times of an ultrasonic signal transmitted by a sensor positioned in a recess at the bottom of the vertical standpipe. Engine power is limited differently based on distinct coolant level states determined based on a change in level of coolant in the reservoir over a duration.

Provided is a hybrid vehicle that includes a power train including an internal combustion engine equipped with a plurality of cylinders and a drive motor unit. The drive motor unit includes an electric motor coupled to the internal combustion engine without a clutch. The internal combustion engine includes one or more decompression devices that are each installed for a subset of one or more cylinders and that operate to release compression pressure in the subset of one or more cylinders in at least one of the course of an engine stop and course of an engine start-up in which combustion is not performed. The subset of one or more cylinders are selected such that, when the one or more decompression devices are operating, compression is not produced sequentially in cylinders that are adjacent to each other in terms of the firing order.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode can include a rocker shaft and a rocker arm. The rocker shaft can define a pressurized oil supply conduit. The rocker arm can receive the rocker shaft and is configured to rotate around the rocker shaft. The rocker arm can have an oil supply passage defined therein. A valve bridge can engage a first exhaust valve and a second exhaust valve. A hydraulic lash adjuster assembly can include first and second plunger bodies, the first plunger body can engage the valve bridge. A pressure relief valve assembly can be configured to selectively release oil from the hydraulic lash adjuster assembly.

An intermittent combustion mode is executed while cyclically switching an intermittent firing pattern in such a manner that the skipped-cylinder interval is changed by one cylinder at a time. Furthermore, the intermittent firing pattern is switched in such a manner that the fired cylinder ratio in one cycle of switching of the intermittent firing pattern becomes equal to a target fired cylinder ratio. This suppresses the occurrence of vibration and noise having low frequencies that tend to disturb the occupant while limiting an increase in the rotational fluctuation of the engine.