A multiple-cylinder diesel engine system comprises an intake valve and an exhaust valve for each of the multiple cylinders. A valve control system is connected to selectively deactivate an intake valve and an exhaust valve for a selected cylinder. A fuel injection control system is connected to selectively deactivate fuel injection to the selected cylinder while increasing fuel to firing cylinders. The multiple cylinder diesel engine enters a cylinder deactivation mode whereby the valve control system deactivates the intake valve and the exhaust valve and the fuel injection control system deactivates the fuel injection to the cylinder while continuing to fire other cylinders of the multiple cylinder diesel engine. The valve control system selectively opens the deactivated intake valve to relieve a negative pressure condition in the deactivated cylinder. Alternatively, the valve control system opens the deactivated exhaust valve to relieve a negative pressure condition in the deactivated cylinder.

An oil supply control device for an engine includes: a hydraulic controller which outputs a control value to an adjusting device to cause a detected hydraulic pressure detected by a hydraulic pressure sensor to coincide with a predetermined hydraulic pressure value; a determination portion which compares an output control value output from the hydraulic controller to the adjusting device when the detected hydraulic pressure coincides with the predetermined hydraulic pressure value and a control value stored in a memory, to determine whether or not a difference between the output control value and the stored control value lies within a predetermined allowable range; and a device controller which allows activation of a hydraulic actuating device when an oil temperature is not lower than a first temperature in a case where the difference lies within the allowable range, inhibits activation of the hydraulic actuating device when the oil temperature is lower than a second temperature higher than the first temperature in a case where the difference does not lie within the allowable range, and allows activation of the hydraulic actuating device when the oil temperature is not lower than the second temperature in a case where the difference does not lie within the allowable range.

In a control device and a control method for a variable valve timing mechanism according to the present invention, the rotational phase of a camshaft is measured based on the cam angle signal and crank angle signal upon receiving each pulse of the cam angle signal, and the rotational phase change over time within a period of the cam angle signal is measured based on the motor angle signal. It is decided whether the cam angle signal and/or crank angle signal has a prescribed pulse pattern at a diagnostic timing that comes after the last pulse of the cam angle signal. When this decision result is positive, it is then decided whether the motor angle sensor operates normally or abnormally based on the rotational phase and the amount of rotational phase change that are measured when the last pulse of the cam angle signal is received before the diagnostic timing.

An oil supply control device includes: a memory which stores first master data constituted by predetermined control value; a hydraulic controller which outputs the control value to an adjusting device to cause a hydraulic pressure to coincide with a target hydraulic pressure; and a determination portion which determines whether or not a first difference between an output control value and the control value of the first master data lies within a predetermined allowable range, wherein the hydraulic controller starts to control the adjusting device with use of the control value of the first master data, when the first difference lies within the allowable range, and starts to control the adjusting device with use of the control value of second master data, when the first difference does not lie within the allowable range, the control value of the second master data causing the first difference to lie within the allowable range.

A switching rocker arm for engaging a cam includes a first arm having a first end and a second end, and a first and a second side arm; a second arm disposed between the first and second side arms, having a first end and a second end, where the second arm is an inner arm. The second arm is pivotably secured adjacent its first end to the first arm adjacent the first end of the first arm. The rocker arm includes an over-travel limiter that limits pivoting motion of the first arm relative to the second arm, where the over-travel limiter is pivotally coupled to the outer arm and interacts with the inner arm.

A rocker arm includes an outer arm having a first side and a second side, an inner arm positioned between the first side and the second side of the outer arm, a pivot axle pivotally coupling the inner arm and the outer arm at a first end of each of the inner arm and the outer arm, and a latch having a first position and a second position. The latch in the first position pivotally fixes the inner arm and the outer arm at a second end of each of the inner arm and the outer arm, and in the second position allows the inner arm and the outer arm to pivot independently. The latch is responsive to hydraulic pressure in a hydraulic fluid passage to selectively move to other of the first position and the second position. A lost motion spring is coupled to the inner arm.

A sensor mounting structure for an engine is provided. The sensor mounting structure offers a greater flexibility in mounting a sensor which detects an operation of an actuation member disposed at an inner wall spaced apart from an outer wall of a cylinder head of a valve gear. A sensor mounting structure for an engine includes a valve gear provided at a cylinder head and a sensor detecting an operation of the valve gear. The sensor is mounted on a sensor mounting hole formed at a head inner wall of the cylinder head covered with a cylinder head cover.

A system includes a rocker arm assembly for operative engagement with a first and second cam. The assembly includes a first arm for operatively engaging the first cam for a first desired lift profile, a second arm for operatively engaging the second cam for a second desired lift profile, where the second arm includes a latch to engage the second arm with the first arm. The latch is responsive to supplied oil pressure and release oil pressure to switch between lift profiles. The system includes the latch coupled to the supplied or released oil pressure to engage the arms before the first and second arms are engaged with the base circle portion of each of the respective first and second cams.

A method of operating an internal combustion engine that includes a valvetrain having a rocker arm assembly including a rocker arm on which a latch pin is mounted. An actuator for the latch pin, including an electromagnet, is mounted separately from the rocker arm. Rocker arm position information is obtained by gathering and analyzing data relating to a current or voltage in an electrical circuit that is operative to power the electromagnet. The rocker arm position information is used to perform a diagnostic.

A system includes a rocker arm assembly for operative engagement with a first and second cam. The assembly includes a first arm for operatively engaging the first cam for a first desired lift profile, a second arm for operatively engaging the second cam for a second desired lift profile, where the second arm includes a latch to engage the second arm with the first arm. The latch is responsive to supplied oil pressure and release oil pressure to switch between lift profiles. The system includes the latch coupled to the supplied or released oil pressure to engage the arms before the first and second arms are engaged with the base circle portion of each of the respective first and second cams.