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

The following procedure is used to test all combination valves.

Special tools, testers and auxiliary items required 

• Hand vacuum pump

Test conditions 

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

Test sequence 

• Remove the vacuum hose from the Secondary Air Injection (AIR) Solenoid Valve N112 - 2  -.
• Connect hand vacuum pump V.A.G 1390 to combination valve vacuum connection - 1  -.
• Disconnect the Secondary Air Injection hose.

Fig 1: Connecting VAG 1390 To Secondary Air Injection Solenoid Valve N112 & Combination Valve Vacuum Connection

Courtesy of VOLKSWAGEN UNITED STATES, INC.

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

• 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.