Combination Valve For Secondary Air Injection, Checking Function And Proper Seal

The following procedure is used to test all combination valves.

Special tools and workshop equipment required 

• Hand vacuum pumpV.A.G 1390
  Fig 1: Identifying Hand Vacuum Pump - V.A.G 1390

  Courtesy of AUDI OF AMERICA, LLC

Test conditions

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

Test sequence

-- Remove the vacuum hose from the combination valve.

-- Connect hand vacuum pumpV.A.G 1390 to combination valve vacuum connection.

-- Remove the air duct hose -arrow- from the Throttle Valve Control Module -J338- and position aside.

-- Disconnect the Secondary Air Injection hose -arrow-.

-- Inject a light air pressure into the in Secondary Air Injection hose to close the combination valve. (do not use compressed air).

• The combination valve should close and seal. Air should not be able to pass through the combination valve.

-- Operate the hand vacuum pump.

• The combination valve should open. Air should be able to pass through the combination valve.

If combination valve does not open:

-- Replace the faulty combination valve.