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

The contact owns a 2017 Mercedes-Benz C300. While driving at approximately 15 mph, the contact observed smoke emanating from under the hood. The vehicle was driven to her work location and parked. Upon exiting the vehicle and opening the hood, she observed orange flames coming from the engine compartment. A parking attendant extinguished the fire, and a police and/or fire report was filed. The vehicle was towed to a dealer and diagnosed with a fuel line leak that caused the engine harness to come apart. The leaking fuel hose from the high-pressure fuel pump caused damage to the high-pressure pump, engine harness, vacuum transducer, and coolant feed line from the thermostat to the firewall. The following components needed replacement: high-pressure fuel pump, rubber fuel hose, engine harness, pressure transducer, and intake manifold. The vehicle was repaired. Five months later, the contact experienced another failure she believes was associated with the engine fire. While parked and attempting to start the vehicle, it did not start. The vehicle was towed to a dealer and diagnosed with a faulty starter that needed replacement. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 65,422.

NHTSA ODI 11738037

Check engine light for P052E which has been coming and going off for years now. Now the check engine light is there permanently. I spoke to Mercedes Benz customer service and requested for them to fix the problem now that the light is on permanently but they refuse to fix it because the car has 222,000 miles on it. This should be a recall from the manufacturer not an extended warranty coverage. The Mercedes dealer in Valencia California told me they now only do a software update and put a plug cap on the sensor and want to charge me $850 even though this should be a recall

NHTSA ODI 11725960

I am reporting a serious vehicle safety hazard caused by improper and unsafe repair work performed by USA Platinum Motor, located at 1221 California Lane #126B, Arlington, TX. I brought my 2017 Mercedes-Benz C300 in for a cold start rattle with no warning lights or prior issues. The shop diagnosed a loose timing chain and I authorized the repair. After the repairs, the vehicle was returned with critical safety defects, including a loose fuel pump, unsecured fuel line, missing bolts, and improperly reassembled engine components. Shortly after pickup, the car experienced loss of acceleration on the interstate, a strong odor of fuel, and a sudden loss of power, creating a dangerous and life-threatening situation. The vehicle had to be towed back to the shop. The manager, who is not a certified mechanic, admitted he personally “fixed” the issue by tightening the fuel pump himself. A Mercedes-Benz diagnostic inspection later confirmed multiple severe assembly errors, including missing fasteners, unsecured oil cooler, disconnected vent lines, and other safety-related defects in the fuel and cooling systems. These unsafe and negligent repairs created an extreme fire hazard, engine instability, and risk of sudden failure while driving. I am requesting a formal NHTSA investigation into this matter to ensure vehicle safety compliance and to prevent similar incidents affecting other consumers.

NHTSA ODI 11696497

ESP control unit software Recall 2016090002 Recall 2017110002 Recall 2020080016 And my car shows there’s cero recall active but is giving me problem showing code: U0121 u1110 U0122 B227d U0423 B227d

NHTSA ODI 11654348

this is my send time writing in. mercedes used the wrong wrist pins for the pistons leading to my wife getting a cracked piston on freeway in phx.if you look up cylinder 1 issues on this model there is a lot of people who have encountered this. why this hasn't been recalled and sticking consumers with a10k plus repair is beyond me. if you use the wrong parts you should be responsible for the repair!!!

NHTSA ODI 11643047

I have an error code: P052E.

NHTSA ODI 11623039

my whole entire car smells like gas. I cannot drive this car around because I will pass out and it is a safety hazard. There is a recall for this exact same issue, just not for my Vin number. I would like to get this done for my car, please.

NHTSA ODI 11621009

Keep getting a code P052E! Changed the oil and code went away for a few days then came back. Looked into getting it fixed and it seems like Mercedes has known about this issue and hasn’t called for a recall on this piece of equipment! Very costly to fix and says it needs to be replaced every 30k to 50k miles! At around 1k to 3k to fix everytime that’s something they should recall

NHTSA ODI 11609586

P052E code for PCV vent valve

NHTSA ODI 11607831

cracked piston in cylinder #1. After doing research this is a common problem in the m274 engine from 2015-2018 which Mercedes is aware of but does nothing. mercedes need to be held responsible and a recall issued. This isn't a 2 or 3 thousand dollar repair!! this repair is 6 figures!!! Please hold them acountable!!! THX

NHTSA ODI 11607748

Check engine light on. Test results: Positive Crankcase Ventilation Regulator Valve Performance CODE : P052E

NHTSA ODI 11603672

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

My engine light keeps coming on and off on my 2017 C300 4matic coupe. I got the problem diagnosed in March 2023. Benz said I had a faulty solenoid valve and that I would need to replace the crank case ventilation assembly. That is $3000. My friend has a C300 sedan and they replaced his under the extended warranty that came out on August 2023 for the crankcase. I have the same exact issue but they said my VIN doesn’t populate so they cannot do anything. This is the 2nd faulty crank case in my car, it was replaced by warranty in 2019. I don’t drive that much I have 47K miles on the car. They refuse to cover the faulty part.

NHTSA ODI 11598324

po52e71 the valve for crankcase ventilation has malfunction

NHTSA ODI 11587623

P052e positive crankcase ventilation regularly valve

NHTSA ODI 11582711

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

Check engine light on on 2017 Mercedes C300 4 Matic. Car has 52,000 miles on it. The code P052E71 was diagnosed by Mercedes mechanic as the valve for the crankcase ventilation. The actuator was blocked. Mechanic said part (crankcase ventilation hose) is not available and this problem happens to all 2015-2017 C 300 models usually around 50,000 miles. When air conditioning or heat is run it causes an odor of burning fuel or oil in the cabin. Mercedes said part is not in stock and they have no ETA on when it will be available. Vehicle is unable to pass vehicle emissions test.

NHTSA ODI 11580115

My Mercedes benz C300 2017 have the P052E positive crankcase ventilation regulatory valve, and Mercedes Benz they start sending this letter and when I go to the dealer they said my car not qualified, but the letter says other thing, my car have the check engine light on with the code PO52E. They don’t want to do the repair because is a $2,500 repair and they making excuses to not do it.

NHTSA ODI 11578049

P052E Positive Crankcase Ventilation Regulator Valve Performance this is a common issue with Mercedes as lots of car are affected by this and this should be covered under emission but lots of dealership are declining saying it’s not covered under emission warranty but this code cause pollution and this part is so expensive to fix and I paid 2k to fix it last year and that same code came again. We can’t keep paying 2k plus for something Mercedes fault design Please help us and make Mercedes Recall this Part

NHTSA ODI 11577903

P052e..PVC ventilation crank shaft valve sensor, too many people all reporting the same expensive item/ labor intensive work by a dealership just after the warranty expires. Help. There are thousands of us with the EXACT SAME CODE AND PROBLEM!! ORDER A RECALL INVESTIGATION!! PLEAS?!?!!!

NHTSA ODI 11576501

The contact owns a 2017 Mercedes-Benz C300. The contact had received notification of NHTSA Campaign Number: 21V032000 (Seat Belts). The vehicle was taken to a local dealer and the recall repair was performed; however, upon retrieving the vehicle, the check engine warning light illuminated upon starting the vehicle. The vehicle was taken back to the dealer and remained in the dealer possession. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 34,000.

NHTSA ODI 11575740

Check engine light came on. Error code indicates a PCV crankcase ventilation valve has malfunctioned. Code is P052E. This is a notorious problem with Mercedes, BMW and other European cars. It should also be considered part of the emissions system. Contacting the MB dealers, I cannot get a clear definition whether it is covered by extended warranties or any warranty whatsoever. They are vague as to "maybe, but not sure". I feel that there should be a recall to fix the defective parts involved with this error code.

NHTSA ODI 11573268

P502e code crankcase ventilation failure

NHTSA ODI 11573103

P052E PCV Regulator Valve Performance

NHTSA ODI 11561010

My vehicle started shaking and the check engine light came on. It's a PCV valve

NHTSA ODI 11558037