What 584 owners told NHTSA about the 2012 Mercedes-benz C-class Coupe

While trying to pass big rig on freeway my car went into lymph mode and stalled causing the car behind me to brake and almost caused an accident. My engine light came on & after getting it checked out I retrieve the following code P0002. After doing some research it appears this is an ongoing issue with this year and model of car.

NHTSA ODI 11534939

The contact owns a 2012 Mercedes-Benz C300. The contact stated that the vehicle was making a loud bang sound towards the rear of the vehicle while driving over bumps in the roadway. The contact took the vehicle to the dealer and was informed that the rear subframe and the rear brake line were severely rusted. The subframe was replaced under an extended warranty coverage; however, the brake line was not covered under the extended warranty. The brake line was not replaced. The manufacturer was made aware of the failure. The approximate failure mileage was 110,000.

NHTSA ODI 11533167

I was driving on the highway and came to a sudden stop and the car fishtailed putting our safety and the safety of others at risk. I brought my car to a mechanic and I changed my tires. When I went for a wheel alignment the mechanic found that the K bar subframe was corroded and cracked. There was no warning prior to the failure. I had no idea there was a problem because the K bar is behind the snow flap and was hidden.

NHTSA ODI 11532607

Recently we had he brakes replaced and new tires put on to prepare for a trip out to Minnesota in a couple of weeks. My son felt like the car wasn’t driving correctly and took it to the shop and upon being put on the lift the service department called and said the rear subframe rusted out and was broken and the gas tank was scratched do to the subframe rubbing against it. When he called Mercedes they told him there was an extended warranty put on these cars which I never received a letter concerning this issue. *The car is waiting to be towed to Mercedes, they would not give us back the keys, it was too dangerous to drive. *my son unknowing drove this car on the highway putting himself and others in danger for who knows how long. If he did not take it in for a check before driving himself and his father to Minnesota they could have been killed. Perhaps a fire due to the gas tank damage. *confirmed by independent repair shop but will be seen when the car is towed to Mercedes. *there was no warning to the dangerous situation my family was placed in. The cars should have been recalled. We were told by Mercedes they were fixing the problem as it arises, luckily no one was injured or killed when this problem arose!

NHTSA ODI 11528670

Dear Sir/Madam, I am writing to file a formal complaint against the Fletcher Jones Mercedes-Benz franchise located in Ontario, California and Mercedes-Benz USA , specifically addressing the issue of the dealership closing the recalls and not honoring the warranty recall on my 2012 Mercedes C250, even though I have received multiple automotive part recall notices for my vehicle. Please see the attached files for more details.

NHTSA ODI 11528628

Dear Sir/Madam, I am writing to file a formal complaint against the Fletcher Jones Mercedes-Benz franchise located in Ontario, California and Mercedes-Benz USA , specifically addressing the issue of the dealership closing the recalls and not honoring the warranty recall on my 2012 Mercedes C250, even though I have received multiple automotive part recall notices for my vehicle. Please see the attached files below for the full story. Thank you for your time.

NHTSA ODI 11528629

on 6/20/23 I was driving this vehicle on the 5 freeway north bound exit 102 in Washington. i found myself travelling at 60mph just moving over to the middle lane of traffic. i needed to slow the vehicle a little and pushing down on brakes I found there was no reaction from the braking system. Making a quick decision I moved over to the emergency lane where I came to a stop. There were no warning signs of the issue. I had the vehicle towed to my Mercedes Benz dealership where I had the car service the day before on 6/19/23 where nothing was noted on this problem. After inspection from the technician at the dealership it was found that the brake vacuum pump was no longer working. Which technician said had caused the issue and he had never experienced this issue before. i am bringing this to your attention due to it could have caused a fatal accident to with me and other people on the freeway.

NHTSA ODI 11528248

Failure of rear subframe causes car to lose control. Only found out about the problem after I received a Mercedes extended Warranty in mail March 2023, roughly 6 months after OEM Undercarriage failed and forced me to purchase another Undercarriage in cash/no insurance involved because part back ordered for many months. Car thus inoperable for roughly 4 months. At moment of the OEM failure, total loss of control. Mercedes refuses to reimburse for cost of replacing undercarriage regardless of the fact that failure occurred before notification and regardless of fact that part unavailable for months

NHTSA ODI 11525268

I found out about the Mercedes Subframe failure issue after having problems on the road, that could have killed me, and being warned not to drive anymore by an authorized repair shop because my vehicle was not safe for me to drive. This has caused many other issues with my cars mechanics due to this defect from the Mercedes factory.

NHTSA ODI 11522182

The drivers door handle broke. In researching online, this has been an issue with Mercedes Benz since they are made of weak plastic. Apparently, they have a more stronger version now. It’s a safety concern as you cannot open the door from the inside.You have to roll down the window, and open the door using the outside handle. What if the power window didn’t work?This is a severe safety concern. If you have to exit the vehicle in a hurry, due to a fire, or accidentally started submerging in water. This should be a recall, we should not have to pay for a replacement to the newer door handle

NHTSA ODI 11521633

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while his wife was driving at an undisclosed speed, she heard an abnormal sound coming from the rear of the vehicle. The vehicle was taken to an independent mechanic where it was diagnosed that the subframe wheel assembly needed to be replaced. No warning lights were illuminated. The vehicle was repaired; however, the contact stated that he received an unknown manufacturer’s recall for the subframe assembly which it was then taken to the dealer, and the contact was informed by the technician that the rear brake line was leaking and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and the contact was informed that the VIN was not included in a recall. The failure mileage was approximately 120,000.

NHTSA ODI 11521006

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving at various speeds, extra brake travel time was needed to stop the vehicle. There was no warning light illuminated. The contact had taken the vehicle to an independent mechanic where the vehicle was purchased, and he was informed that the failure was caused by the new brake pads placed on the vehicle. The contact eventually took the vehicle to a dealer and was informed that the fuel tank and brake lines were corroded; and the contact was provided an estimate for the repair. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 96,000.

NHTSA ODI 11518035

The rear subframe rusted prematurely and broke off important mounts for the suspension and steering. I was driving and had to hard brake. This cause the back end of the car to swerve and almost lose control. I then heard a knocking sound when I pressed the brakes, prompting me to take it into the shop. There I was informed the the subframe was rusted and the vehicle wasn’t safe to drive. I filed a claim with my insurance, but they said it’s wear and tear.

NHTSA ODI 11517601

I was driving on the freeway and had to hard brake due to unexpected stopped traffic. When I braked the vehicle veered hard to the left and almost lost complete control of the car and nearly caused a serious accident. I drove immediately to a local MB dealer and they confirmed what I was afraid and suspected which was the right rear subframe needs replaced. This car was recently sold to me by a dealer less than a month ago and not a single warning light or indicator warning me of this issue. The repair is over 7500 and the shop highly recommended I no longer drive until it’s replaced. This problem is very common and MB actually covers the cost in Europe and Canada.

NHTSA ODI 11515333

The left rear weld of the subframe on my 2012 C300 4matic has rotted through and appears to be a manufacture's part defect. I found out about this issue from a brake inspection and told it is a safety concern, which Mercedes Benzes is aware of but has no recalls for the defect.

NHTSA ODI 11513818

Popping sounds and smoke from center dash and right rear speaker. Center speaker magnet extremely hot to the touch.

NHTSA ODI 11513427

It is a wide-spread issue and commonly known issue that when the car battery is replaced in Mercedes-Benz vehicles, the climate control stops working, as well as the blower. The safety issues: •Car battery needed to be replaced during non-daylight hours during the winter. •Climate control stopped working immediately upon battery replacement, and issues with blower arose. •I drove home in the dark, during winter, without the ability to defrost my windows. A quick Google search for this issue will uncover an abundance of consumer complaints and common themes regarding this issue.

NHTSA ODI 11511741

The contact owns a 2012 Mercedes-Benz C250. The contact stated while starting the vehicle, the vehicle started very rough with a rattling sound coming from the vehicle. The check engine warning light illuminated. The vehicle was not diagnosed. On another occasion, while opening the front driver’s side door, the door handle fractured. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was 90,000.

NHTSA ODI 11511575

A problem with the rear subframe had occurred in which it had started to rust. Due to the severity of the issue I noticed my car started veering when hitting the brakes as well multiple concerning sounds and stability issues with the vehicle. Mercedes has not contacted me about replacing the part nor has their been any warning lights or any indication of the issue being present other than when the subframe had already been rotted. When speaking to MB about the issue their was nothing they could do for me which is questionable being that the cause of this is a manufacturing issue. I have yet to receive any information as to how the issue may be resolved. Not only does this put myself at my family at risk but as well as the community around me. Wether when braking my vehicle may veer and cause a collision or an issue where the subframe fails and causes an accident.

NHTSA ODI 11511486

The subframe assembly on my car is defective, as I learned today from my mechanic. This issue is known for my model of car and widely reported online. The mechanic says they have seen this issue before. I heard a strange noise while driving so I took the car to the shop after 60 days of enduring the sound. The shop immediately deemed the car unfit for driving and unsafe. In their words, if I had hit one bad pothole, the wheels could have come off the back of my car, and my gas tank could have been punctured, leading to a potentially catastrophic accident. I am lucky to have gotten this defective part identified before being injured, and others need to be protected from this outcome before a serious injury occurs. As of now this has only been inspected by the shop doing the fix. People online have indicated that Mercedes will not fix the problem free of charge - and in fact they charge a premium to other places to replace this faulty subframe. There were zero warning indicators of this dangerous issue - the car drove completely normally aside from an infrequent knocking sound that would occur every 5-10 minutes under normal city driving conditions.

NHTSA ODI 11509955

My vehicle had started swerving when I had hit the brake. I noticed that my rear subframe had been rotting and did more research only to find that this was a common problem amongst Mercedes Benz owners. This is a huge safety issue as not only does it put my cars entire suspension at risk and cause a life threatening accident to me or others on the road it is also very concerning when my vehicle creaks and makes constant noises when driving. There are times it feels as if my vehicle’s suspension will fall out from under it and has been a clear issue Mercedes is aware of yet I have not received any recall notice nor have I gotten any answer as to how Mercedes can help me fix an issue they continuously overlook and sweep under the rug. I fear that eventually something will happen and have been trying to get an answer as to how to get my vehicle repaired without it coming back on me since the root of the issue lies in MBUSA parts snd not on my own doing.

NHTSA ODI 11509704

The contact owns a 2012 Mercedes-Benz C300. The contact stated that while driving approximately 55 MPH and pressing the brake pedal, the entire vehicle shifted to the left. Additionally, while driving at various speeds the vehicle was unstable and experienced vibration. The vehicle was taken to an independent mechanic who discovered that the subframe of the vehicle had severe rusting and corrosion and that the vehicle was unsafe to operate. The vehicle was not yet repaired. The local dealer and manufacturer were not notified of the failure. The failure mileage was 95,000.

NHTSA ODI 11509340

My car’s left side rear subframe is cracked due to corrosion. I started hearing a weird noise a week ago, and my car suddenly veered to the left side when I pressed the brake. I almost crashed my car because the car moved to the left of the yellow line on the road. I searched about this issue on Google and found that many C-Class owners (W204 generation) are experiencing the same issue due to the design flaws/defects by Mercedes-Benz. Now I have to pay up to $10,000 for the repair that is due to a defective part. In other countries like the UK and South Korea, this issue is covered by Mercedes-Benz, but in the United States, it is not covered. The repair is done at owner’s expense. I fear driving now because my car steers to the left when I press the brake. The rear subframe must be recalled since this issue is now common to all C-Class models produced in 2008-2014, and if car accidents occur, many people can be killed. I almost crashed my car due to my rotten subframe. Please help.

NHTSA ODI 11509103

The contact owns a 2014 Mercedes-Benz C250. The contact stated while driving 70 MPH, there was an abnormal frequency sound coming from the speakers followed by a popping sound. The contact then began to smell a burning electrical wiring odor with white smoke coming from the middle dashboard speaker. The contact immediately pulled over and turned off the vehicle. There was no warning light illuminated. Due to the failure, the contact called her father who towed the vehicle to her home where it remained in her possession. The contact reached out to the manufacturer by email and was informed that there were no recalls on the VIN. The contact was then referred to the NHTSA for further assistance. The vehicle was not repaired. The failure mileage was approximately 305,000.

NHTSA ODI 11508516

The contact owns a 2012 Mercedes-Benz C250. The contact stated that she noticed that the air bag warning light was illuminated. The dealer was contacted because the vehicle had been serviced under NHTSA Campaign Number: 21V638000 (Air Bags) and the dealer stated that the seat belt was malfunctioning. The vehicle was not repaired. The manufacturer was contacted, and a case was filed. The failure mileage was 78,000.

NHTSA ODI 11506437