Combination Valve, Checking

Diagnostic Procedures

Combination Valve, Checking

Special tools, testers and auxiliary items required

• Hand Vacuum Pump (VAG1390)

Test requirements

• No leaks in vacuum lines or hose connections.

• Vacuum hoses not clogged or kinked

• Connection hose between combination valves and pressure hose for Secondary Air Injection (AIR) Pump Motor not clogged or kinked.

• Ignition switched off.

Test sequence

- Disconnect vacuum hose of combination valve to be checked:

• Combination valve, cylinder bank 1 ,

• Combination valve, cylinder bank 2.

• Cylinder bank 1 = in driving direction, right.

• Cylinder bank 2 = in driving direction, left.

- Connect hand vacuum pump to corresponding vacuum connection of combination valve.

- Remove pressure hose from connection line.

• Do not use pressurized air for the following test!

- Blow with light pressure into connection line.

Both combination valves must be closed.

- Operate hand vacuum pump.

The respective combination valve must open.

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

- Replace the respective combination valve:

• Combination valve, cylinder bank 1 ,

• Combination valve, cylinder bank 2.

- Erase DTC memory of Engine Control Module (ECM) , Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code.