Motor-Boost Pressure Servo: Description
WARNING: This page is about a different car, the 2006 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The turbocharger boost pressure servomotor is bolted to the side of the turbocharger housing and is responsible for controlling turbocharger boost pressure. It controls the boost pressure by varying the position of the guide vanes. The servomotor operates in response to a PWM signal from the ECM.