VANOS Solenoid Control
Control of the VANOS solenoids is an output function of the MS S52 control module. There is an inlet and exhaust solenoid for each camshaft. These solenoids are both installed on one side of the control piston. The engine control module regulates the solenoids through a pulse width modulated signal to apply or drain control oil pressure from the VANOS pistons.
Camshaft adjustment is based on several characteristic maps stored in the control module. The main control parameters for camshaft adjustment are derived from the the engine speed signal and the throttle valve position signal.