Combination valve for Secondary Air Injection (AIR), checking function and proper seal

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and equipment

Fig 1: Identifying Hand Vacuum Pump V.A.G. 1390

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VAG1390 Hand vacuum pump

Requirements

Vacuum lines and hose connections leak-free.
Vacuum lines not clogged.

Work sequence

Fig 2: Removing Rear Engine Cover

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Remove rear engine cover (arrows).

Fig 3: Removing Bolts For Holding Plate For Solenoid Valves

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Remove bolts for holding plate for solenoid valves (arrows).
Lift up holding plate and disconnect vacuum hose from Y-piece of combination valve to be checked.
Connect VAG1390 hand vacuum pump to vacuum hose of combination valve to be checked.

Fig 4: Identifying Exhaust Pipe Fasteners

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For vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of auxiliary heater at sound insulation.

Fig 5: Identifying Quick-Release Fasteners And Noise Insulation

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Remove bolts or release quick-release screws -1- and -2- and remove front sound insulation.

Fig 6: Disconnecting Pressure Hose At Secondary Air Injection (AIR) Pump Motor And Blow Into It With Light Pressure

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Disconnect pressure hose (arrow) at Secondary Air Injection (AIR) pump motor and blow into it with light pressure (do not use pressurized air).

Both combination valves must be closed, it must not be possible to blow through hose

Operate hand vacuum pump.

Relevant combination valve must open, it must be possible to blow through

If the relevant combination valve does not open:

Replace combination valve. Refer to Left combination valve for secondary air injection, removing and installing or Right combination valve for secondary air injection, removing and installing .