NHTSA Complaint #11699978 — 2014 MERCEDES-BENZ CLA250

I own a 2014 Mercedes-Benz CLA 250 with the 2.0L turbocharged 4-cylinder M270 engine. The check-engine light came on and an OBD-II scan showed fault code P052E / P052E71, which indicates that the valve for crankcase ventilation (PCV / crankcase ventilation valve integrated into the valve cover) has a malfunction and the actuator is blocked. The vehicle is available for inspection and, if the repair is performed, the failed part can be retained. This appears to be the same failure that has been documented by other owners and by Mercedes-Benz on the related M274 engine used in other models (same 2.0L turbo engine family and PCV / crankcase ventilation design, but in a longitudinal layout). For those vehicles, Mercedes has issued technical service bulletins and extended emissions-related warranty coverage for the crankcase ventilation / PCV system, but vehicles like my CLA with the M270 engine are excluded even though they show the same DTCs and failure. In my case, the problem has so far shown up as a check-engine light and stored fault codes, without obvious drivability symptoms yet. However, a blocked or failed crankcase ventilation valve can increase crankcase pressure, cause oil leaks, fuel vapor or oil smells, and potential turbocharger or drivability issues, which may create a safety risk if the problem worsens (loss of power or stalling). The problem has been reproduced multiple times with different OBD-II scan tools. I contacted Mercedes-Benz and was told there are no recalls or warranty coverage for this issue on my vehicle.