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
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:

NOTE:

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.

NOTE:

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:

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

-- Generate readiness code.