Operation CHARM: Car repair manuals for everyone.

Combination Valve, Checking






Combination Valve, Checking

The following procedure is used to test all combination valves.

Special tools, testers and auxiliary items required

• Hand vacuum pump.





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.





- 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.