Control of an electromagnetic steering valve of a camshaft phaser

A movable valve apparatus for adjusting an air control valve of an internal combustion engine, comprising:

• a movable valve mechanism operatively controlled by hydraulic pressure of a working fluid to adjusting the air control valve;
• a hydraulic pressure control valve operatively coupled to the movable valve mechanism to adjust the hydraulic pressure of the working fluid supplied to the movable valve mechanism, the hydraulic pressure control valve includes a spool reciprocally coupled within a sleeve to control the hydraulic pressure of the working fluid supplied to the movable valve mechanism;
• and
• a controller operatively coupled to the hydraulic pressure control valve to drive and control the spool within the sleeve, the controller being configured to execute a foreign object removal operation upon the controller determining that the spool is in a returning state in which the spool starts moving toward an initial position, the spool being temporarily reciprocated by the controller to remove foreign objects inside the hydraulic pressure control valve during the foreign object removal operation.