Air Injection Control Valve: Testing and Inspection

GLC EXC. CALIFORNIA

1. Remove air filter cover and air filter.
2. Disconnect vacuum hose from air control valve.
3. Run engine at idle.
4. Apply intake manifold vacuum directly to air control valve and ensure air is drawn through reed valve inlet port of air cleaner.
5. Ensure volume of air entering reed valve inlet port in step 4 decreases when intake manifold vacuum is not applied.
6. If test results are unsatisfactory, replace air control valve.