2014 Mercedes-Benz CLA250: sudden loss of power

Filed Nov 17, 2025 · Engine · PA

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.

Filed Sep 26, 2024 · Electrical, Engine · 76,850 miles · OK

The contact owns a 2014 Mercedes-Benz CLA250. The contact stated while driving at approximately 70 MPH, the vehicle stalled. The contact stated that when the vehicle stalled, an audible chime sounded, and the air bag warning light illuminated, and a RED triangle symbol flashed on the instrument panel. The contact stated that the instrument cluster went blank, and the vehicle lost power steering assist. Additionally, the brake pedal was very difficult to depress. The contact was able to restart the vehicle after several attempts, and the vehicle returned to normal functionality. The contact stated that the failure reoccurred. The contact drove the vehicle to a dealer who diagnosed the vehicle and determined that the battery needed to be replaced. The vehicle was repaired. The contact stated that the failure reoccurred and the vehicle had not taken back to the dealer. The manufacturer was not informed of the failure. The failure mileage was 76,850.

Filed Jun 17, 2022 · Brakes, Electrical · NY

I just got the vehicle it’s losing power already, I was driving up a hill as a school bus was behind me, and my car started losing power and rolling back. I have a transmission issue they sold it this way also electrical.

Filed Mar 12, 2017 · 24,000 miles · FL

On several occasions,in the rain under acceleration;the car goes into limp mode-check engine light comes on and you have no power to get out of traffics way. All but one case,the car returned to normal after a shut down and restart. In one instance,the check engine stayed on. When a dealer inspected the car they found no cause -(code said engine misfire )-the light was reset-since that dec.2016 dealer visit the problem has happened twice leaving the car to lose power while in highway traffic. A recent dealer visit (no engine light on ) resulted in their finding no issue. This is very dangerous,and not without many other similar complaint. Lives are in the balance here-we need government oversite-please!

Filed Jul 14, 2016 · Transmission · 40,000 miles · CA

Tl* the contact owns a 2014 mercedes-benz cla250. While driving 25 MPH, the vehicle lost power. The accelerator pedal was depressed, but the vehicle failed to accelerate. The brake, ESC, and multiple warning lights illuminated. The vehicle was taken to a dealer, but the contact was unsure about what part was replaced. The vehicle was repaired, but the failure recurred. The vehicle was taken back to the dealer who was unable to diagnose or repair the vehicle. The failure persisted. The manufacturer was notified of the failure. The failure mileage was 40,000.

Filed Nov 10, 2015 · Driver assistance · 19,000 miles · MD

My car suddenly slowed and I lost power while driving on 95 at approximately 20-30 MPH in slow heavy traffic to work this morning. I could hardly accelerate and only slowly... I had messages that said "pre-safe functions inoperative. See operator's manual", and the ESC light came on. Drivers behind me started passing me despite me already going slowly due to all the traffic--I had no where to pull over and crawled into the parking ramp at work. I could have been rear-ended this morning. I have no idea what will happen when I restart the car today. This needs to be taken care of by mercedes--do a recall and fix this issue!

Filed Oct 14, 2015 · Electrical · MD

Brought cla250 6/2015 after three months loss power, engine light came on car decelerated. Took vehicle to the dealership after 3 different incidents, to be told there was a service bulletin on my car. Will keep you posted after pick up. Car was at the stop light and the vehicle deceleration went down.

Filed Apr 10, 2015 · Engine · 25,000 miles · KS

Vehicle suddenly lost power while driving at approximately 30 MPH. Only able to accelerate very slowly. Messages "inoperative see operator's manual" and "pre-safe functions limited" displayed. It is unsafe that car suddenly decelerates without warning to surrounding drivers. This has happened on two separate occasions a few days apart.

Filed Mar 9, 2015 · Engine · 17,515 miles · NY

Tl*the contact owns a 2014 mercedes cla250. The contact stated that while driving at 55 MPH, the vehicle lost power as the engine warning light illuminated. The failure recurred several times. The vehicle was taken to the dealer. The technician was unable to diagnose the failure. The manufacturer was not notified of the failure. The failure mileage was 17,515.

Filed Feb 24, 2015 · Engine · 220 miles · AL

I was driving on the interstate the car lost all power. On the dash board it read inoperative see manual. The can would not move. I almost got kill in the traffic. On 02/23/2015 I was driving on the interstate again the same thing happen again. Each time I took the car to the dealer. I am afraid to drive this car because it is very dangerous.

Filed Jan 9, 2015 · Acceleration, Engine · TX

The pre safe mode has happened 5 times on my cla 250 since I bought the car last january. I think the pre safe mode is not safe at all. All of a sudden, the car just lost power, no any feedback when I stepped the gas pedal, the best thing is the brake still worked. After restarting the car, the car went well but the engine light was on. However, after two days, the engine light was off so I didn't even have a chance to show to the dealer. It's very dangerous to drive this car on high way, especially in traffic jam.

Filed Jan 4, 2015 · Driver assistance, Engine · 13,000 miles · FL

Vehicle's transmission & throttle response is jerky & unpredictable. Rotors went bad at 5,000 miles, beginning to go bad again at 12,000. Numerous unknown interior rattles.windshield wiper completely flew off vehicle while driving in heavy rain - visibility instantly reduced to near-zero. On two occasions, the car displayed "pre-safe functions limited/esp inop" message followed by engine immediately losing power on freeway, which could have ended very badly. Not only is this vehicle of poor quality, it is becoming increasingly dangerous to drive. Seriously considering pursuing state lemon law.