A method of determining a sliding camshaft actuator pin position based on engine crankshaft angle includes commanding a sliding camshaft actuator to perform a valve step shift, and monitoring an actuator's pin position during the valve step shift command. At least one crank angle is measured when the actuator pin position reaches or exceeds at least one predetermined pin position threshold and at least one remedial action is performed when the actuator pin position does not correlate to the at least one measured crank angle.

A method is provided for operating a three step camshaft system during engine position sensor fault conditions. The three step camshaft has multiple cam actuators each having an actuator pin. The method includes: disposing multiple camshaft barrels on a camshaft, each barrel having a slot receiving the actuator pin of a cam actuator during camshaft barrel rotation axially displacing each camshaft barrel to a high lift lobe position, a low lift lobe position and an active fuel management (AFM) lobe position; determining if an engine position sensor is in a fault condition; identifying if the fault condition occurs simultaneously with any of the camshaft barrels positioned in the AFM lobe position; energizing selected cam actuators in communication with the camshaft barrels positioned in the AFM lobe position to axially displace the camshaft barrel away from the AFM lobe position and to the low lift lobe position.

An internal combustion engine system is provided with a cam switching device including a cam groove provided on the outer peripheral surface or a camshaft and an actuator capable of protruding, toward the camshaft, an engagement pin that is engageable with the cam groove. The internal combustion engine system is configured, in causing the cam switching device to perform a cam switching operation, to control the actuator such that the engagement pin is seated on a forward outer peripheral surface which is located more forward than an end of the cam groove on the forward side with respect to an insert section of the cam groove in the rotational direction of the camshaft.

The invention relates to an improved system of electro-mechanical hydraulic valve lifters for piston engine automobiles that increases fuel economy and reduces fuel emissions. The electro-mechanical hydraulic valve lifters enclose a magnetorheological fluid chamber, containing magnetorheological fluid. A control module manages voltage sent to the magnetorheological fluid in the magnetorheological fluid chamber. The control module introduces various amounts of magnetic flux to the magnetorheological fluid in the magnetorheological fluid chamber. The magnetorheological fluid's viscosity changes based on the amount of magnetic flux applied to it from the electromagnets and, along with the magnetorheological fluid chamber spring, controls how much an intake and exhaust port of the spark plug engine opens to control the amount of fuel used and exhaust let out of the engine.

A continuously variable valve timing (CVVT) control device is provided. The CVVT control device includes an engine controlling unit (ECU) configured to output an actual phase angle and a target phase angle of an intake valve or an exhaust valve. The CVVT control device further includes an intellectual motor controller configured to receive the actual phase angle and the target phase angle from the ECU through digital communication in a vehicle. A driving current is generated for adjusting an output torque of a motor based on a phase deviation between the received actual phase angle and target phase angle.

The invention relates to an improved system of electro-mechanical hydraulic valve lifters for piston engine automobiles that increases fuel economy and reduces fuel emissions. The electro-mechanical hydraulic valve lifters contain that enclose a magnetorheological fluid chamber, containing magnetorheological fluid. A control module manages voltage sent to the magnetorheological fluid in the magnetorheological fluid chamber. The control module introduces various amounts of magnetic flux to the magnetorheological fluid in the magnetorheological fluid chamber. The magnetorheological fluid's viscosity changes based on the amount of magnetic flux applied to it from the electromagnets and, along with the magnetorheological fluid chamber spring, controls how much an intake and exhaust port of the spark plug engine opens to control the amount of fuel used and exhaust let out of the engine.

It is intended to, when abnormality in either one of two rotation detection sections with different detection frequencies occurs, quickly and highly accurately detect the abnormality to favorably deal with abnormality occurring during low engine rotation. It is determined that abnormality is present in the rotation phase detection section, when an absolute value of difference between an actual VTC angle detected by a rotation phase detection section and an integrated value of a VTC change angle detected by motor rotation sensor 201 with the higher detection frequency than the frequency of detection of the actual VTC angle by the rotation phase detection section is equal to or greater than a predetermined value.

A method for controlling continuously variable valve timing (CVVT), may include determining whether a CVVT control is started, detecting a position of a cam and a position of a crankshaft when the CVVT control is started, determining whether the cam is positioned at a locking position based on the positions of the cam and crankshaft, determining whether the cam is controlled to be positioned from the locking position to an advancing position or a holding position, when the cam is positioned at the locking position, and when the cam is controlled to be positioned from the locking position to the advancing position or the holding position and when a condition for performing the CVVT control is satisfied, determining whether a cam torque is negative and performing predetermined CVVT control after waiting a predetermined time when the cam torque is negative.

It is intended to, when abnormality in either one of two rotation detection sections with different detection frequencies occurs, quickly and highly accurately detect the abnormality to favorably deal with abnormality occurring during low engine rotation. It is determined that abnormality is present in the rotation phase detection section, when an absolute value of difference between an actual VTC angle detected by a rotation phase detection section and an integrated value of a VTC change angle detected by motor rotation sensor 201 with the higher detection frequency than the frequency of detection of the actual VTC angle by the rotation phase detection section is equal to or greater than a predetermined value.

A variable valve system including a crank angle sensor that measures a rotation angle of a crankshaft, a cam angle sensor that measures a rotation angle of a camshaft coupled to the crankshaft and which opens and closes valves, and a controller that controls the internal combustion engine. At least one of the crank angle sensor or the cam angle sensor is configured as an absolute angle sensor that measures an absolute rotation angle and outputs a voltage signal corresponding to this rotation angle. The controller is configured to perform a correction operation that corrects a rotation angle value calculated based on the voltage signal.