Home · 2017 Mercedes-benz C-class Phev · Complaints

What 251 owners told NHTSA about the 2017 Mercedes-benz C-class Phev

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (251)Crash / fire / injury (19)Engine (82)Electrical system (35)Fuel system (35)Body & structure (26)Seat belts (26)Airbags (18)Steering (15)Transmission & drivetrain (15)Visibility & wipers (11)Wheels (6)

15 of 251 complaints match · Transmission & drivetrain · clear filters

Jan 13, 2025Transmission & drivetrain

PVC VALVE CODE. P052E Mercedes should fix this!

NHTSA ODI 11635775

Jul 10, 2024Transmission & drivetrainEngine

Car check engine light came on with only 62,000 miles. Diagnosed as code P052E, the issue is the positive crankcase ventilation valve being faulty. Regular oil changes and maintenance was done. I see multiple complaints with this issue, why is this not recalled? It is very expensive to have fixed.

NHTSA ODI 11601009

Mar 29, 2024Transmission & drivetrainEngine

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while at a stop light the vehicle stalled. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the battery cable needed to be replaced. The vehicle was repaired but the failure recurred. The vehicle was taken back to the local dealer where it was diagnosed that an update to the powertrain software was needed, and the transmission pump needed to be replaced. The vehicle was repaired but the failure persisted. The contact called the local dealer, and it was recommended that the transmission be replaced. The vehicle was not repaired. The manufacturer was contacted. The failure mileage was approximately 80,000.

NHTSA ODI 11580064

Dec 15, 2023Transmission & drivetrain

Positive Crankcase ventilation

NHTSA ODI 11560289

Jan 10, 2023Transmission & drivetrainEngineFuel system

I purchased my 2017 C300 class Mercedes-Benz ("MB") in May 2021 from a used car dealership in Mobile, AL. At that time it had 36,000 miles. Less than 2 years later, on or about 12/15/22, as I was driving, the MB suddenly and without warning began to vibrate violently and immediately lost power. The car had @54,000 miles on it. I routinely drive interstate to and from work and had just gotten off of the interstate. I was lucky that I was driving at a low speed when this happened; otherwise, a serious accident could have resulted. I took it to the local MB dealership which told me that the car failed a compression test in the #1 cylinder and that the engine would have to be replaced. Subsequent research on the cause of this total engine failure with low mileage revealed that this engine has a chronic piston defect that damages the #1 cylinder, causing it to lose compression, and that MB has known about the defect for many years, an issued an internal bulletin about it. MB has not alerted the public nor instigated a recall. I was not informed by MB at any time that the C300 class engine had a chronic piston defect that would damage the #1 cylinder which would, in turn, cause the engine to lose power and the vehicle to vibrate and shake, creating a dangerous diving condition under all circumstances, but especially if the car was being driven at speed on a federal interstate highway. Despite demands by me and others, MB refuses to responsibly address the issue. The driving public is, and remains, clearly, in great risk of harm due to this defective engine and associated power train issues. It is patently unreasonable for MB to produce and market such a unsafe, dangerous and defective product that poses an unreasonable risk of harm to its customers and others when being used as it was intended. I understand that the NHTSA has opened an investigation on this defect and wish for my voice to be heard on it. Please contact me [XXX] for further details. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

NHTSA ODI 11500998

Sep 5, 2022Transmission & drivetrainEngine

My car threw the check engine code P052E, the issue is the positive crankcase ventilation valve being faulty. Incredibly common on this model and now failed on my car too at 60K miles. All maintenance was done up to this point with the dealer and at or before recommended intervals.

NHTSA ODI 11482918

Aug 31, 2022Transmission & drivetrainEngine

My car leaked oil very fast while me & my wife were on a trip and it stopped on the highway and engine was stalling and misfiring due to a manufacture defect that is common with this model so it did put us in a very dangerous & risky situation. Now after i paid $1,740 the dealer is saying that my car needs a new engine due to cracked piston in cylinder 1 that damaged the engine which is a common problem with this model around the 50k miles.

NHTSA ODI 11482136

Jul 13, 2022Transmission & drivetrain

My check engine light keeps jumping off and on, went to get diagnosed and the PCV valve came back. I’m not sure why

NHTSA ODI 11473703

Apr 18, 2022Transmission & drivetrainEngineFuel system

At approximately 26,500 miles of use, the check engine light came on in my Mercedes Benz C300. I brought the vehicle to the dealership and they informed me that the diagnosis was a crankcase vent valve malfunction. The MB fault code is P52E71. After paying Mercedes to fix the issue, I found forums on the internet where many other MB owners reported the same issue at around the same mileage. Being that this seems to be a common malfunction with the C300, I believe that it should be considered as a recall issue. I don't know what could have happened if I didn't service the vehicle, but any engine issue is dangerous while a vehicle is in motion.

NHTSA ODI 11461236

Mar 24, 2022Transmission & drivetrain

electronic rear axle lock problem. A recall was issued before but manufacturer has not done anything; therefore when the car is taken in, the dealer asks for a hefty $400 inspection fee

NHTSA ODI 11458248

May 11, 2021Transmission & drivetrainEngine

VEHICLE JERKS VERY VIOLENTLY WHEN ACCELERATING OR USING PADDLE SHIFTERS (IN MANUAL MODE). OTHER OWNERS SEEM TO ENCOUNTER SAME ISSUE

NHTSA ODI 11416040

Mar 13, 2021Transmission & drivetrainElectrical systemEngine

WHEN THE CAR IS IN THE A FEATURE, WHERE IT TURNS ON AND OFF WHEN NOT IN MOTION, IT GETS STUCK IN THAT MODE AS IF A MAGNET IS HOLDING IT IN THAT POSITION. IT WILL NOT MOVE, IT STALLS. I TURN IT OFF AND TURN IT BACK ON AND SOMETIMES IT STILL WILL NOT MOVE, SOMETIMES, IT WILL NOT TURN BACK ON. THIS HAS HAPPENED ON SEVERAL DIFFERENT OCCASIONS. ONCE, I PULLED TO THE SIDE OF MY MAILBOX TO PICK UP MAIL, AND ANOTHER OCCASION I PULLED INTO MY GARAGE, AND IT STOPPED, AND WOULD NOT TURN ON. THIS IS VERY DANGEROUS, I WOULD HATE TO BE IN TRAFFIC, RAILWAY CROSSING, IR STOP SIGN AND THIS OCCURRED. PEOPLES LIVES HAVE BEEN LOST DUE TO THIS ISSUE. ONE LADY WAS HIT BY A TRAIN WHEN THIS SAME SITUATION OCCURRED AND LOST HER LIFE. I AM VERY CONCERNED FOR MY SAFETY AND OF MY GRANDKIDS WHOM I TRANSPORT IN THIS CAR. IT ALSO SEEMS THAT SOMETHING IS WRONG WITH THE GEARS. SOMETIMES, I PUT IT IN REVERSE AND IT SITS THERE. I PUT IT IN DRIVE AND IT WILL NOT MOVE. I FEEL VERY UNSAFE IN THIS VEHICLE. PLEASE HELP.

NHTSA ODI 11402743

Apr 24, 2019SteeringTransmission & drivetrainElectrical system

ON 7/30/18 I WAS STRANDED IN THE MIDDLE OF THE STREET AFTER THE COOLANT MALFUNCTION LIGHT CAME ON. THE CAR BEGAN OVERHEATING, AND THERE WAS NO AC. I WAITED FOR ROADSIDE ASSISTANCE MORE THAN 3 HOURS. I WAS INFORMED OF THE INCORRECT POSITIONING OF THE ALTERNATOR FROM MANUFACTURING, WHICH RESULTED IN MULTIPLE LIGHTS ON CLUSTER. THEY FOUND THE ENGINE BELT FELL OFF & REPLACED THE V-BELT. THEY PERFORMED LI13.22-P-060187, AND RELEASED STRESS OF ALTERNATOR AND CORRECTED TORQUE. THEY ALSO WORKED ON A CAMPAIGN/RECALL (#2018070005) I HAD NOT BEEN INFORMED OF. ON 3/15/19 DURING THE SCHEDULED 20K SERVICE, THEY TESTED BATTERY TEST CODE WITH CABIN FILTERS WIPERS AND BRAKE FLUID SERVICE AND PERFORMED A VEHICLE INSPECTION. ON 3/19/19, 4 DAYS AFTER THE SCHEDULED 20K SERVICE, I WAS STRANDED IN THE MIDDLE OF US1 DURING RUSH HOUR TRAFFIC ON MY WAY TO WORK. THE COOLANT LIGHT CAME AGAIN. THANKFULLY, I SAFELY AVOIDED AN ACCIDENT AFTER THE CAR TURNED OFF IN THE MIDDLE OF THE STREET. THE REPORT SHOWED A WEAK CRANK & BATTERY MESSAGE ON THE CLUSTER DISPLAY. THEY TESTED THE BATTERY AND FOUND CODE HR250BT-DAD4LFB STATING, 'REPLACE BATTERY'. THEY REMOVED A0019820208 DATE 45/16 AND INSTALLED A0019829108 DATE 03/18. THE DRIVE BELT HAD COME OFF THE DRIVE SYSTEM & FOUND LI13.22-P-060187, WHICH STATED THEY NEEDED TO PERFORM AN ALIGNMENT PROCEDURE OF THE ALTERNATOR AND INSTALLED A NEW BELT FOR THE 2ND TIME. THE BELT ACTUALLY CAUSED DAMAGE TO THE TENSIONING DEVICE, WHICH RESULTED IN THEM REPLACING THE TENSIONER, AND PERFORMING THE INSTRUCTION FOR LI. THEY TEST DROVE THE CAR & SAID IT WAS FIXED. ON 4/4/19, JUST 3 DAYS AFTER PICKING UP MY CAR, IT TURNED OFF ON MY AGAIN IN THE MIDDLE OF US1. THE BATTERY LIGHT CAME ON AND A MESSAGE POPPED UP STATING THAT THE SYSTEM WOULD SHUT DOWN IN 3 MINUTES. I WAS LUCKY ENOUGH TO AVOID AN ACCIDENT ON A CONGESTED ROAD.

NHTSA ODI 11203356

Apr 18, 2019Transmission & drivetrain

WHEN IDLING AT THE LIGHT. THE CAR WOULD SHUT ITSELF OFF. ALL THE WARNING LIGHTS WILL COME ON. I THEN HAVE TO RESTART THE CAR WITH THE PUSH START TO RESET IT. THEN IT'LL WORK FINE. I HAVE BEEN TO MERCEDES DEALERSHIP IN NEW ROCHELLE FOR FOUR TIMES ABOUT THIS ISSUE. THEY CHANGED THE BATTERY THE FIRST TIME. TWO DAYS LATER THE SITUATION OCCURRED AGAIN. THEN THE SECOND AND THIRD TIME THEY GAVE ME BACK THE CAR AND SAID THEY DIDN'T SEE ANYTHING WRONG BECAUSE NO CODES POPPED UP. BOTH TIMES I TOOK THE CAR BACK AND THE SITUATION OCCURRED AGAIN. THIS PROBLEM HAS OCCURRED OVER 30 TIMES SINCE OVER 29,000 MILES. THE DEALERSHIP IS TRYING TO FIGURE OUT THE ISSUE AND RIGHT NOW I AM IN A LOANER VEHICLE ON THE FOURTH TIME THAT I HAVE GIVEN MY CAR IN FOR SERVICE BECAUSE OF THIS SITUATION. THE INCIDENT IS DANGEROUS IN THAT ONE TIME I WAS IN AN INTERSECTION AND IT SHUT OFF ON ME. CARS GOING THE OPPOSITE WAY ALMOST HIT ME BECAUSE OF MY REACTION TIME TO PUT THE CAR ON START AND THEN RESTART THE CAR. THIS CAN BE POTENTIALLY DANGEROUS FOR POSSIBLE ACCIDENTS. IN ADDITION, I HAVE LOOKED ONLINE AND SIMILAR PROBLEMS HAVE OCCURRED WITH OLDER MODELS AND OTHER MODELS.

NHTSA ODI 11197127

Nov 26, 2017Transmission & drivetrainElectronic Stability Control (esc)Engine

THE CAR ENTERS LIMP MODE IN THE HIGHWAY WHERE IT LOOSES ALL THE POWER AND WARNING POPS UP AS ACTIVE BRAKE ASSIST IS INOPERATIVE, TRACTION CONTROL LIGHTS COME ON AS WELL. IF YOU MANAGE TO GLIDE THE CAR TO A STOP AND RESTART THE CAR, THE CAR STARTS TO BACK UP AS NORMAL. TOOK THE CAR FOR SERVICE SEVERAL TIMES, INTAKE AIRFLOW SENSOR WAS REPLACED BUT THE CAR STILL HAS THE SAME ISSUE. UPON SEARCHING ONLINE, THIS IS A VERY WELL KNOWN ISSUE WITH THE NEWER MECEDES CARS WHERE THE CAR GOES INTO A SAFETY MODE WHERE THE ENGINE CUTS ALL THE POWER TURNING THE SITUATION INTO A EVEN MORE DANGEROUS SCENARIO. AS PART OF THE SAFETY MODE, IF THE CAR LOOSES ALL THE POWER, THEN THERE IS FEW THINGS THAT CAN BE DONE TO COME OUT OF IT. THIS IS A MAJOR SAFETY CONCERN AS REPEATED OCCURENCE OF THIS PROBLEM HAS THE ABILITY TO CAUSE A SEVERE ACCIDENT.

NHTSA ODI 11048503

Working with the data? Download all 251 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2017 Mercedes-benz C-class Phev verdict →