Positive Crankcase Ventilation (PCV) System

Run engine at idle. Remove ventilation hose from PCV valve, hissing noise should be heard from hose and a strong vacuum should be felt immediately when finger is placed over valve inlet. If not, check hose and hose connections for leaks or obstructions. Check PCV valve. Service or replace as necessary.

Fig 1: Component Test Chart Symbol Identification

Courtesy of NISSAN MOTOR CO., U.S.A.