2012 Mercedes-Benz C-Class
Problems, recalls and owner-reported issues
Air bags is the leading concern among 587 owner complaints filed for this model year. This is the 3rd highest complaint count among 23 C-Class model years with reports.
Of the 2012 reports, 8 involved a crash and 7 involved a fire. 10 people were injured and 1 person died.
What owners report most often
Recalls and investigations
No safety recalls on file.
Representative owner complaints: other or unspecified
36 reports, newest first. Show all
Structure, Other or unspecified, Aug 20, 2025
Rear subframe rotted out and broke due to corrosion. Rear crossmember is broken and needs replaced. My safety as well as the safely of other was put at risk. Loss of control at high speed could have been deadly. Luckily, I wasn’t going very fast at the time of incident or else who knows what would have happened to me or bystanders. Independent service center inspected and confirmed that incident was due to corrosion in the rear. They informed me of the extended warranty (20 years, unlimited miles) on 2008-2015 C300 models for this particular issue as my safety and the safety of others was put at risk. There were some symptoms leading up to the incident. At the time of braking the car would become unstable and feel skittish in the rear. It felt as if the rear was sliding to one side. The vehicle would also make some metal clinking noises at sharper turns. The symptoms had been more frequent in the prior 2-3 months of incident. The vehicle has been inspected and diagnosed by one shop and is currently getting a second opinion from another independent service center.
Other or unspecified, Jul 24, 2025
The electronic steering lock failed resulting in my car being completely disabled. My safety was not at risk in this particular instance. I was left stranded in a parking lot at night. The component was not inspected by the manufacturer or dealer. The manufacturer/dealer did not inform anyone that this problem will happen to every car with this compensation. This component failed without warning/symptoms/messages. It will fail on all Mercedes Benz cars from 2008-2016. The problem has not been confirmed or communicated by the dealer. Other Mercedes benz owners have encountered this problem resulting in their cars being disabled and leaving them stranded.
Electrical system, Other or unspecified, Engine, Jan 27, 2025
1. The car radio, blue-tooth, speakers, sound, car remote sound. Happened after a battery change by AAA - unsure if it's related. CUstomer service tried to resolve it - radio turns on, but nothing else works. 2. Doors won't unlock outside or inside - except passenegers side is open. 3. Accelerator acting strange - won't pick speed after 30, then 60 4. there was an air bag recal of this car a while ago.
Other or unspecified, Feb 19, 2024
Took my 2012 Mercedes c300 to my mechanic and the Rear Sub frame is rusting out.
Suspension, Other or unspecified, Oct 21, 2023
My rear subframe has corroded and has snapped, which is a major safety issue as while driving when I come to a stop the rear end of the car swags sideways. It do not stop straight.
Other or unspecified, Oct 6, 2023
I started hearing noises about a week ago while driving. Last night while driving home in the evening traffic, I braked and car violently jerked and veered to the right almost hitting the car in the front. I took the car to a shop this morning and they found that the rear subframe had collapsed due to rust and advised the car was extremely dangerous to drive.
Suspension, Wheels, Other or unspecified, Sep 23, 2023
Rear driver side wheel was making a clicking noise leading us to believe there was an issue with the strut and/or shock. Due to the nature and severity of the noise, we took the vehicle to our mechanic ASAP. Upon inspection, mechanic identified that the sub-frame had completely rusted through which could lead to other catastrophic issues making vehicle no longer safe to drive unless repaired. Due to the age of the vehicle being 11 years old, the cost to repair was almost the value of the vehicle basically making this a complete loss. I understand that Mercedes Benz has extended the warranty to 20 years for this issue for other models identifying that it is a design/parts defect but not the C300 although I have found that this is also an issue for this model.
Other or unspecified, Jul 16, 2023
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.
Other or unspecified, Jun 24, 2023
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.
Other or unspecified, Jun 24, 2023
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.
Other or unspecified, May 12, 2023
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
Electrical system, Other or unspecified, Mar 23, 2023
Popping sounds and smoke from center dash and right rear speaker. Center speaker magnet extremely hot to the touch.
Other or unspecified, Visibility/wiper, Mar 14, 2023
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.
Other or unspecified, Feb 9, 2023
My vehicle has 70,000 miles. always kept garaged. Told by dealer when taken for the yearly checkup that the rear subframe of the car is totally rotted. Needs replacement. Price $3790. Mercedes would only cover 20% of the cost. There have been recalls in Canada with the same issues. Please investigate as this is a serious defect problem and not a warranty issue as Mercedes is claiming.
Other or unspecified, Feb 8, 2023
Premature subframe rust, causing the vehicle to swerve when brakes are applied looks to be a trend: https://www.benzworld.org/threads/2012-c300-rear-subframe-any-updates-on-recall.3086018/page-6
Suspension, Structure, Other or unspecified, Jan 16, 2023
Cradle and subframe are completely rusted out. This a widely common issue with these cars and am reading it across several forums. Other c300 owners say they have had the exact same issue and request for the MB dealership to fix it. Instead they are given a quote of nearly $10,000 to fix it. MB is responsible for this.
Other or unspecified, Dec 9, 2022
The sub frame broke in half and the dealership said it is due to rust. The car has been garage kept and not driven much at all. It’s a 10 year old car with only about 55,000 miles on it. It’s been used very gently.
Other or unspecified, Nov 20, 2022
I purchased a 2012 Mercedes C300 AWD from a local dealer and have had it serviced annually. Last week I took it in for the annual servicing and was told by the dealer that the rear subframe had corrosion /rust and the car was not safe to drive. I asked if it was covered under a recall and they said not by Mercedes at this time.They provided a repair estimate that is quite high and close to the appraised value of the car. I asked if there were any options available through Mercedes or the dealer and they confirmed not at this time. I have read many articles related to this problem and imagine there are many complaints on file at NHTSA. This is obviously a serious safety issue and currently Mercedes is not taking responsibility and directing the costs to their customers. In addition there is a subframe parts shortage and it could take weeks to fix. I'm requesting that this be listed as a recall item by Mercedes.
Suspension, Structure, Other or unspecified, Oct 10, 2022
Rare Subframe breaking off parts are not available for at least 6 months. I have kids and mechanics advise me to keep it off the road. My only means of transportation
Other or unspecified, Sep 23, 2022
the rear subframe rotted away
Other or unspecified, Sep 16, 2022
The W204 subframe of my Mercedes Benz C Class is failing and in need of repair, this should not be happening to a car with less than 80K miles on it. My local auto repair shop which exclusively services Mercedes Benz currently has two vehicles with the same issue and informed me that the subframe part is currently out of stock due to the number of failures. This issue has caused a recall in other countries. What is the NHTSA doing about this issue. I will be contacting my congressional representative today as well.
Suspension, Other or unspecified, Aug 5, 2022
2012 Mercedes Benz C300 4-Matic; Failure of rear subframe, significant crack of an important support member; very limited minor corrosion of the other parts of the frame, seems to be a manufacturing quality defect in a very specific part. Vehicle has been inspected by a highly qualified independent mechanic and by the closest manufacture's dealer in Massachusetts. Car cannot be driven because it is unsafe to do so. Both the dealer's service department and the independent repair shop have advised and confirmed this. Limited research online seems to indicate that this problem is well known by Mercedes Benz, and the manufacturer has issued recalls in other countries and has taken some responsibility for this defect. However, in the USA, Mercedes Benz has not issued a recall, to the best of my knowledge. It certainly seems that they should have done so. It is highly likely that many owners with this problem lack the knowledge or experience needed to report this problem to the appropriate authorities. I happen to have an above average knowledge regarding automobiles. I first became aware of this problem in Nov., 2021. The vehicle is available for inspection by your department if you deem appropriate.
Other or unspecified, Jun 22, 2022
Rear Subframe Rot- this seems to be a common and known issue with Mercedes’ that should be a recall. Yet Mercedes is charging almost $6000 to get this fixed at the dealer. Plus the parts are on back order for months. This is causing cars to sway when stopping. This is definitely a hazard and should be addressed ASAP!
Other or unspecified, Jun 11, 2022
The rear subframe on my 2012 Mercedes Benz C300 was corroded and broke. This caused the car to lose control and easily could have been been life threatening at high speeds. Mercedes Benz is clearly aware of this issue and knows this is a part defect but has not been willing to do a recall in the US even though they have done so in other countries. The dealership has told me this needs to be repaired as the car can’t be driven, so I am not happy I need to pay $5,000 out of pocket for a part defect Mercedes knows about and refuses to issue a recall even though this problem can cause a fatal accident. There were no warning signs besides hearing thumping sounds and the instability caused by the part defect when it finally failed and broke.
Steering, Suspension, Other or unspecified, Apr 7, 2022
I drove over an object on the highway and noticed my car veering left and wobbly when turning. A week after, it is squealing like a load of piglets in my trunk whenever I go over a bump, then my battery light came on and I took it to the shop and contacted my insurance, who denied my claim saying it was 'wear and tear'.