Which of the following is not part of the crankcase emission controls on diesel vehicles?

• A. Exhaust Gas Recirculation (EGR)
• B. Positive Crankcase Ventilation (PCV)
• C. Crankcase Depression Regulator (CDR)
• D. Crankcase Ventilation (CCV)

Answer: (A)

Exhaust Gas Recirculation is not part of crankcase emission controls because its job is different: it reduces NOx by routing a portion of the exhaust back into the intake, lowering combustion temperature. Crankcase emission controls, on the other hand, deal with vapors that escape from the crankcase. They manage these blow-by gases either by returning them to the intake (Positive Crankcase Ventilation) or by venting them through a controlled breather path (Crankcase Ventilation) or by regulating the crankcase vacuum (Crankcase Depression Regulator). So while PCV, CCV, and CDR are all about handling crankcase vapors, EGR targets exhaust gases and the combustion process, not the crankcase emissions.