Combination Valves, Checking

Combination Valves, Checking

Recommended special tools and equipment
- VAG1390 Hand Vacuum Pump

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.

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:
- Combination valve, cylinder bank 1,
- Combination valve, cylinder bank 2-.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes