Boost Pressure Control Flap Actuator, Basic Function - GF09.50-P-2001A

Engine All (4xWD) 

Engine All (CAR) 

Overview 

This document contains information on:

• General 
• Function 
  • Exhaust gas turbocharger with variable blade geometry
  • Exhaust gas turbocharger with fixed blade geometry

General 

The boost pressure control flap actuator is responsible for raising or reducing boost pressure via the exhaust gas turbocharger.

As Engine speed increases, the exhaust gas volume increases, which directly influences the rotational speed of the turbine wheel in the exhaust gas turbocharger. To ensure that the exhaust gas turbocharger operates within the specified delivery limit with regard to the Engine operating point, boost pressure control via the boost pressure control flap actuator is required.

Function 

Exhaust gas turbocharger with adjustable turbine geometry 

After evaluation of the input signal, the CDI control unit regulates the position of the boost pressure positioner according to a characteristics map. According to the actuation, the boost pressure regulator adjusts the position of the guide vanes, which are positioned in a circular manner on a carrier ring that is connected via a shaft to the adjustment ring. The adjustment ring is in turn connected via the linkage to the boost pressure control actuator. The adjustable guide vanes modify the flow cross-section through which the exhaust gas flows to the turbine. The positioning travel of the actuator motor is determined via an integrated, inductive sensor.

Exhaust gas turbocharger with fixed turbine geometry 

Boost pressure control is implemented by means of a continuous adjustment (adjustment angle of between 0 and 109°) of the boost pressure control flap. The boost pressure control flap actuator actuates - via a linkage - the boost pressure control flap that closes the bypass. Part of the exhaust flow is directed through the bypass past the turbine wheel, whereby the boost pressure is regulated and the turbine speed limited. In this way the boost pressure can be adapted to the current load demand on the Engine. The positioning travel of the actuator motor is determined via an integrated, inductive sensor.

A DC motor, an induction-type sensor and an actuator housing are accommodated in the housing of the boost pressure control flap actuator.

	Component descriptions
	Wastegate pressure transducer, component description	Model 223	GF09.40-P-2155A
		Model 206	GF09.40-P-2155C
		Model 232	GF09.40-P-2155F
		Model 254	GF09.40-P-2155H
		Model 214	GF09.40-P-2155K
		Model 167 as of model year 2023	GF09.40-P-2155M
		Model 192	GF09.40-P-2155R
		Model 236	GF09.40-P-2155S
	Component description for boost pressure actuator	Model 223	GF09.40-P-4020A
		Model 464	GF09.40-P-4020J
		Model 118, 177, 247 as of model year 2023	GF09.40-P-4020L
		Model 167 as of model year 2023	GF09.40-P-4020M