Overview plan of exhaust turbocharging system (Vehicles with engine code AWD)

The following list pertains to Fig 1.

1. Connection hose 
   • From the Leak detection pump (LDP) -V144-
2. Vacuum reservoir 
   • below front right wheel housing liner
3. Check-valve 
4. Turbocharger 
5. Check-valve 
6. Vacuum diaphragm 
   • For boost pressure regulator valve
7. Deceleration shut-off valve 
8. Wastegate Bypass Regulator Valve - N75- 
   • Valve is activated (pulsed) by the Engine Control Module (ECM)
   • Closed when no voltage present, limits charge pressure
   • Checking, see WASTEGATE BYPASS REGULATOR VALVE, CHECKING 
9. Brake booster 
10. Check-valve 
    • For brake booster
11. Air filter with Mass Air Flow (MAF) Sensor -G70- 
12. Pressure regulator valve for crankshaft housing ventilation 
13. Combination valve 
    • For Secondary Air Injection (AIR) system
    • Checking, see COMBINATION VALVE, CHECKING
14. Fuel pressure regulator 
15. Check-valve 
16. Recirculating valve for turbocharger -N249- 
17. Secondary Air Injection (AIR) Solenoid Valve -N112- 
    • Checking, see SECONDARY AIR INJECTION (AIR) VALVE, CHECKING
18. Crankshaft housing ventilation 
19. Check-valve 
20. Charge Air Pressure Sensor -G31- Replace O-ring when damaged 
    • Checking, see CHARGE AIR PRESSURE SENSOR, CHECKING 
21. Secondary Air Injection (AIR) Pump Motor -V101- 
    • Checking function, see SECONDARY AIR INJECTION (AIR) PUMP MOTOR, CHECKING
22. Charge air cooler 
23. Vacuum reservoir 
24. Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- 
    • Checking, see EVAPORATIVE EMISSION (EVAP) CANISTER PURGE REGULATOR VALVE, CHECKING
25. Connection hose 
    • to EVAP canister
Fig 1: Overview Of Exhaust Turbocharging System (Vehicles With Engine Code AWD)
Courtesy of VOLKSWAGEN OF AMERICA, INC.