Audi AMB Service Manual page 218

ENGINE 1.8 Liter 4-Cyl. 5V Turbo Engine Mechanical, Engine Code(s): AMB
21 - Recirculating valve for turbocharger N249
Component location: Below intake manifold

22 - Vacuum diaphragm for boost pressure regulation
When combination valve is opened, mechanical boost pressure regulation valve in turbocharger is opened

and secondary air is thereby channeled past turbocharger directly to catalytic converter
Boost pressure regulation and vacuum control system, connection diagram for vehicles as of 07.03
Fig. 289: Boost Pressure Regulation And Vacuum Control System, Connection Diagram For Vehicles As
Of 07.03
Courtesy of VOLKSWAGEN UNITED STATES, INC.
1 - Resonator
2 - Mechanical recirculation valve
3 - Secondary Air Injection (AIR) Pump Motor V101
2005 Audi A4 Quattro
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