Boost pressure regulation and vacuum control system, connection diagram for vehicles up to 06.03
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Boost Pressure Regulation And Vacuum Control System, Connection Diagram For Vehicles Up To 06.03
1 - Mechanical recirculation valve
2 - Wastegate Bypass Regulator Valve N75
3 - Pressure regulator valve for crankshaft housing ventilation
4 - Secondary Air Injection (AIR) Pump Motor V101
5 - Air filter
- With Mass Air Flow (MAF) Sensor G70
6 - Check valve
- Installed position: Arrow on valve points in direction of flow, as shown in illustration
7 - To EVAP canister
8 - Evaporative Emission (EVAP) Canister Purge Regulator Valve N80
9 - Turbocharger
10 - Combination valve for secondary air injection (AIR)
11 - To brake booster
12 - Check valve
- Installed position: Arrow on valve points in direction of flow, as shown in illustration
13 - Check valve
- Installed position: Arrow on valve points in direction of flow, as shown in illustration
14 - Crankshaft housing ventilation
15 - Vacuum reservoir
- Component location: Under wheelhousing liner in front left wheelhouse
16 - Check valve
- Installed position: Arrow on valve points in direction of flow, as shown in illustration
17 - Secondary Air Injection (AIR) Solenoid Valve N112
- Component location: Below intake manifold
18 - To Leak Detection Pump (LDP) V144
19 - Check valve
- Installed position: Arrow on valve points in direction of flow, as shown in illustration
20 - Charge air cooler
- With Charge Air Pressure Sensor G31
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