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

WARNING: This page is about a different car, the 2006 Audi A8, 2005 Audi A8, and 2004 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.

Special tools, testers and auxiliary items required

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

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Hand vacuum pump V.A.G 1390

Test requirements

Vacuum lines and hose connections free of leaks.
Vacuum lines not plugged.

Test sequence

Fig 2: Removing Engine Cover

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove engine cover - 1 - upward.

Fig 3: Disconnecting Vacuum Hose At Combination Valve To Be Tested

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Disconnect vacuum hose - arrow - at combination valve to be tested.
Connect hand vacuum pump V.A.G 1390 to vacuum hose of combination valve to be checked.

NOTE:

Illustration depicts engine from rear.
Left combination valve is shown in illustration.

For vehicles with parking/auxiliary heater:

Fig 4: Removing Bolts For Exhaust Pipe Of Parking Heater/Auxiliary Heater On Noise Insulation

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Remove bolts - arrows - for exhaust pipe of parking heater/auxiliary heater on noise insulation.

All

Fig 5: Locating Mounting Parts And Removing Noise Insulation

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Remove noise insulation - 1 -.

Fig 6: Disconnecting Intake Air Duct At Secondary Air Injection (AIR) Pump Motor V101

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Disconnect pressure hose - 2 - at Secondary Air Injection (AIR) Pump Motor V101 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.

The relevant combination valve must open, it must not be possible to blow through

If relevant combination valve does not open:

Replace combination valve, left → Secondary Air Injection (AIR) (left combination valve), removing and installing or right → Secondary Air Injection (AIR) (right combination valve), removing and installing .