Diagnosis of a leakage in the PCV-System

A disconnection or leakage in the PCV-System is indicated by a rough or stalling engine and results in a reaction within the fuel system (fuel trim deviation).

In this case a fault code will be stored by the fuel system monitoring. 

Fig 1: PCV-System Diagram

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Identifying Intake Air System, Blowby Tube And Cylinderhead Cover With Integrated Oil Separator

Courtesy of BMW OF NORTH AMERICA, INC.