Combination Valve, Checking

WARNING: This page is about a different car, the 2008 Volkswagen R32. However, it is still accessible from the selected car via links, so may be relevant.

The following procedure is used to test all combination valves.

Special tools and workshop equipment required

Hand vacuum pump.

Fig 1: Hand Vacuum Pump - V.A.G 1390
Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Test conditions

secondary air injection (AIR) solenoid valve -N112- OK.
secondary air injection (AIR) solenoid valve 2 -N320- OK
Check vacuum system, including vacuum reservoir in intake manifold, for leaks.
Check that the vacuum lines are correctly connected.
Check the vacuum hoses for damage.
Vacuum lines not plugged.

Test sequence

-- Remove the vacuum hose from the combination valve.

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

Fig 2: Connecting Hand Vacuum Pump V.A.G 1390 To Combination Valve Vacuum Connection

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

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

Fig 3: Disconnecting Secondary Air Hose

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- 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.