The solenoid valve is a proportional valve with four connections, one connection each to the oil pump and return, as well as to the two working chambers of the camshaft phasing unit. When current is applied to the electromagnet, this moves the internal control slider in the valve and thus switches the oil pressure between the working chambers. The working chamber not subjected to oil pressure at a particular time is connected to the return. In order to fix a timing position, the valve is hed in the so-called centre position, in which case the lines are separated from all the connectors.
The valve is compact but of a modular design and permits modification to match the particular application. The position and type of the plug as well as the type of oil feed (lateral or end face) are flexible.