An engine can be damaged if operated without a crankcase ventilation valve. Perform the Functional Check at intervals shown in Section 0B of the appropriate service manual or the maintenance schedule of the vehicle. Refer to Crankcase Ventilation System Diagnosis -Crankcase Ventilation System Functional Test.

Replace the crankcase ventilation components as the diagnosis requires. The recommended replacement parts are listed in the Specifications section of the owner manual of the vehicle.

Periodically, inspect the hoses and clamps. Replace any showing signs of deterioration.