The pneumatic actuator A of the boost pressure control valve is controlled by the electromagnetic valve B, which is controlled by the injection system ECU. Depending on the engine operating mode, the electromagnetic valve changes the vacuum supplied to the pneumatic actuator, which ensures the boost pressure regulation.
In the initial position, the boost pressure control valve is open. In this case, the engine operates without turbocharging.
The electromagnetic valve is closed in its initial position and control voltage is supplied to it after the engine is started with some time delay depending on the coolant temperature.
(Original of this article on the website: renaultbook.ru)