Combination Valve, Checking

Special tools and workshop equipment required

Test requirements

No leaks in vacuum lines or hose connections.
Vacuum hoses not clogged or kinked
Pressure and intake hose for Secondary Air Injection (AIR) Pump Motor not clogged or kinked.
Ignition switched off.

Test sequence

-- Disconnect vacuum hose from Secondary Air Injection (AIR) Solenoid Valve -N112- at combination valve (arrow).

Fig 1: Locating Vacuum Hose At Combi-Valve

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Connect hand vacuum pump (VAG 1390) to vacuum connection of combination valve (arrow).

Fig 2: Hand Vacuum Pump VAG 1390 Connected To Vacuum Hose From Combi-Valve

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

NOTE:

Do not use pressurized air for the following test!

-- Disconnect pressure hose (arrow) from Secondary Air Injection (AIR) Pump Motor -V101- at pressure line.

Fig 3: Disconnecting Pressure Hose From Secondary Air Injection (Air) Pump Motor -V101- At Pressure Line

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Attach assisting hose onto pressure line and blow into with light pressure.

Combination valve must close.

-- Operate vacuum pump.

Combination valve must open.

If the combination valve does not open or it is constantly open:

-- Replace combination valve.

Final Procedures

After the repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .