The boost pressure is determined by the speed of the supercharger turbine. Turbine speed control is based on signals from the CDL control unit
boost pressure sensor (B5/1) sends the pressure data to the CDI control unit, which controls the vacuum converter of the turbocharger control actuator.
In vehicles about PR numbers (MF4) n (MF8) boost pressure is controlled by turning the turbine guide vanes, and in Euro 3 engines, a bypass damper control is used.