What solenoid valve is on the cover of BMW 3 Series engine?

The cover plate of BMW 3 Series engine is turbocharger solenoid valve.

At low speed, the solenoid valves at the connecting end and the pressure limiting end B make the pressure regulating device automatically adjust the boosting pressure; During acceleration or high load, the solenoid valve is powered by the engine control unit in the form of duty ratio, and the low-voltage end is connected with the other two ends, so the pressure drop reduces the opening of the diaphragm valve and the exhaust bypass valve of the booster pressure regulating unit and increases the booster pressure. The greater the boost pressure, the greater the duty cycle.

The pressure control of the supercharging limit solenoid valve N75 is controlled by the engine control unit ECU. In the turbocharger system with exhaust bypass valve, the solenoid valve will be controlled according to the engine control unit ECU.

Indicates the opening time for controlling atmospheric pressure. According to the pressurization pressure and atmospheric pressure, the control pressure acting on the pressurization tank is generated. The exhaust bypass valve overcomes the spring pressure and the exhaust flow is separated. From a part of the turbine

Shunt, another part of the wastegate valve that enters the exhaust pipe is not used. When the power supply fails, the solenoid valve will be closed, and the boosting pressure will directly act on the pressure tank.