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
587 reports, newest first.
Structure, Other or unspecified, Mar 14, 2022
Vehicle was in for state inspection at an authorized inspection station. It failed inspection due to severely rusted and deteriorated rear K-Frame which had to be replaced to pass inspection. This is a major defect I feel caused by manufacture negligence. There were no warnings, messages or any signals indicating a problem. This issue could have severely caused an injury or even death had it not been detected by the mechanic inspector. Mechanic stated to me that he had replaced several of the rear K-Frames in the last year on this make and model.
Structure, Mar 6, 2022
While driving recently we noticed that the vehicle pulled to one side while braking, and very hard under quick stop tests. Vehicle handling felt extremely dangerous when performing a hard brake test. An inspection was performed, and the service center found a rotted out rear subframe, and cracking around the suspension mounting brackets. After researching this repair, we found this to be a common problem in this and similar model Mercedes-Benz (MB) vehicles of that vintage. I understand that a recall may have been issued in Canada regarding this issue, but not in the U.S. Mercedes-Benz and their service stations have acknowledged this issue is common but they have not taken action to rectify this serious problem, or to compensate owners for the repair costs, which range from $3500 to $6000 depending on where the vehicle is serviced. We are the first owners of this car. It is barely 10 years old, is regularly maintained, and thoroughly washed during the winter months to remove road salt. A well maintained vehicle should not deteriorate this rapidly from rust, especially a Mercedes-Benz. We feel that it is unacceptable for MB to remain unaccountable for this problem.
Suspension, Feb 26, 2022
Rear subframe failure caused me to loose control of vehicle almost resulting in a serious highway accident. Rear driver side stabilizer subframe mount was completely corroded and broken away from the subframe. There is no other significant corrosion on the subframe. MB claim normal corrosion however the pictures tell a different story.
Suspension, Feb 24, 2022
While performing service inspection, technician found REAR SUB FRAME RUSTED AND READY TO BREAK. Told they needed to show me the problem on the lift, as it was a serious SAFETY ISSUE and should be IMMEDIATELY REPLACED. Dealer and service acknowledged that this is a KNOWN and WIDESPREAD PROBLEM in C Class vehicles. Cost to replace quoted at $4200. No warning - thankfully inspection found before I was in a serious accident! Mercedes should issue recall for failed/corroded frame. Not the "safe" vehicle that Mercedes claims. (Car has been dealer serviced regularly, garaged, and 34,000 miles.) Owners shouldn't have to suddenly come up with $4,200 in order to drive their seemingly normal car. DANGEROUS.
Engine, Feb 24, 2022
The engine in my car died and after inspection by a Mercedes mechanic they concluded the failure was caused by faulty camshafts that have been common in the year and model this car. Mercedes has issued and extended warranty to cover the repairs recognizing this was a manufacturing issue but they are refusing to cover the full cost of repairing my car.
Structure, Feb 14, 2022
Per the dealership in connection with a regular service, the rear subframe rusted out and became structurally weak and was a safety hazard. The problem was confirmed and repaired by an independent repair shop. From Google searches, this issue does not appear to be an uncommon problem. Car is garaged and receives regular underbody washes for road salt.
Steering, Electrical system, Jan 24, 2022
While driving, engine stopped, could not steer.. Looks like a defective Electronic Ignition Switch or steering lock! It seems to be a common problem on these cars!!! The car would not start. After 8 attempts, I was able to start car but was afraid to drive it. Could have been a disaster.
Vehicle speed control, Fuel/propulsion system, Fuel system, Gasoline, Jan 20, 2022
2012 C250 has a known defect with high pressure fuel pump. I personally have had an intermittent issue where vehicle will unpredictably stop working under heavy throttle and enter limp mode as the computer throws a fault code. This results in loss of power after the code making vehicle unpredictable and dangerous in passing situations. It leaves you stranded in the passing lane with oncoming traffic with a vehicle that will not accelerate. I have submitted a request multiple times with Mercedes benz corporate who has declined my submission. This issue has been ongoing since 2016. They have offered an extended warranty on the vehicle 10 years and 120,000 miles as they know there is a defect. It is dangerous and needs to be covered for all of the affected vehicles.
Structure, Jan 7, 2022
This is a followup to a previous report. I now have photos and the actual part that was replaced. While driving on secondary road at 45 mph, braked for stoplight in 2012 Mercedes C300 4matic. Car veered left, rear swung right, and right front dove downward. Luckily regained control and prevented swerving into oncoming traffic. Took car to my regular mechanic and it was determined that the welds on the left rear portion of the rear subframe had rusted out from the inside of the subframe, severing the attachment to the left rear wheel control arms. The car had been inspected 6 months earlier and there was no sign of problem. The failure was catastrophic, not gradual. Upon removal, it was also noted that the right mounting bracket was also in the process of rusting through and failing. When the mechanic called the local Mercedes dealer, the service manager was not surprised and proceeded to outline what parts would be needed to carry out the repair. When I contacted the local Mercedes dealer, myself, they said this wasn’t an uncommon problem, but there was not recall or service bulletin on the problem. Was given a rough quote of $5000 to affect the repair. I also contacted Mercedes Benz USA and was told there were no recalls or service bulletins, but they might be able to provide some “Goodwill Assistance” to offset the expected cost if I had it towed to a MB dealer and got a quote from them. Benzworld.org, an owners forum with over 5 million participants world-wide https://www.benzworld.org/threads/w204-rear-subframes-deterioration.3048088/#post-17965564 has multiple postings about the problem as do other forums including CarProblemZoo.com https://www.carproblemzoo.com/mercedesbenz/c300/suspension-problems.php . This design/manufacturer defect has had recalls in both Europe and Canada. Why this is not being addressed in the US? This sudden failure is potentially life-threatening.
Suspension, Dec 30, 2021
The rear subframe rusted through causing mounting point of the torque link to fail. As a result, the car looses control when braking going sideways. Luckily, I discovered it when testing brakes after pad replacement in a safe setting. To my understanding, there are many other W204/W212 cars affected in the US with that issue. Mercedes so far does not want to take responsibility and recall cars for this issue which is a huge concern.
Electrical system, Air bags, Dec 16, 2021
3 signal Signal light comes one saying abs, another SRS MALFUNCTION, also crushed control inoperable. Car will come one as normal next day car comes on no lights not 1 button work turn signals didn’t work then my car fan came on in the engines the also the when they the electric isn’t working i have to manually shift the gear
Electrical system, Dec 13, 2021
Electronic Steering Lock (ESL) fails and your key fob nor your keyless go button will function, rendering your car unable to start...! Usually it's the cheap toy motor that engages the moving tab that locks and unlocks the column and communicates to the ignition to start the car... You get only a message to "remove your key" and the dash lights will not come on nor can you start the vehicle... Mercedes is aware of this, as there are thousands of complaints on this ESL issue... Mercedes needs to issue a recall and do away with this faulty ESL module...!!!! Oh by the way, they charge $1500+++ to fix it...
Structure, Dec 13, 2021
The contact's wife owns a 2012 Mercedes-Benz C300. The contact stated that upon taking the vehicle to the dealer to be serviced, he was informed that the subframe was severely corroded and could fracture. The manufacturer was notified of the failure and advised the contact that they could not assist as the vehicle was out of warranty. The vehicle was not repaired. The approximate failure mileage was 43,000.
Structure, Nov 26, 2021
While driving on secondary road at 45 mph, braked for stoplight in 2012 Mercedes C300 4matic. Car veered left, rear swung right, and right front dove downward. Luckily regained control and prevented swerving into oncoming traffic. Took car to my regular mechanic and it was determined that the welds on the left rear portion of the rear subframe had rusted out from the inside of the subframe, severing the attachment to the left rear wheel control arms. The car had been inspected 6 months earlier and there was no sign of problem. The failure was catastrophic, not gradual. When the mechanic called the local Mercedes dealer, the service manager was not surprised and proceeded to outline what parts would be needed to carry out the repair. When I contacted the local Mercedes dealer, myself, they said this wasn’t an uncommon problem, but there was not recall or service bulletin on the problem. Was given a rough quote of $5000 to affect the repair. I also contacted Mercedes Benz USA and was told there were no recalls or service bulletins, but they might be able to provide some “Goodwill Assistance” to offset the expected cost if I had it towed to a MB dealer and got a quote from them. Benzworld.org, an owners forum with over 5 million participants world-wide https://www.benzworld.org/threads/w204-rear-subframes-deterioration.3048088/#post-17965564 has multiple postings about the problem as do other forums including CarProblemZoo.com https://www.carproblemzoo.com/mercedesbenz/c300/suspension-problems.php . This design/manufacturer defect has had recalls in both Europe and Canada. Why this is not being addressed in the US? This sudden failure is potentially life-threatening.
Structure, Nov 23, 2021
The contact owns a 2012 Mercedes-Benz C300. The contact stated her son was driving approximately 60 MPH and noticed that the steering wheel was crooked and vibrating. The driver was manually turning the steering wheel for the vehicle to drive straight. The driver also noticed that while depressing the brake pedal, the rear of the vehicle was shaking going from left to right while coming to a complete stop. The driver took the vehicle to an independent mechanic to be inspected and was informed that the rear driver’s side subframe had separated from the vehicle due to extreme rust. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 115,000.
Engine, Nov 17, 2021
The contact owns a 2012 Mercedes-Benz C250. The contact stated that while driving at 50 MPH, the check engine warning light illuminated. The contact was able to continue to drive the vehicle. The vehicle was taken to an independent mechanic who diagnosed that the variable valve timing solenoid had failed and needed to be replaced. The dealer was notified of the failure and advised the contact that he would be responsible for the cost of the diagnostic test. The manufacturer was notified of the failure through a voicemail message. The vehicle was not repaired. The approximate failure mileage was 52,000.
Vehicle speed control, Engine, Fuel/propulsion system, Nov 13, 2021
When accelerating to pass a vehicle the check engine light comes on and there is loss power. When this happens there is a huge potential of a crash. The car has to be shut off to try and reset this. When you are on the frwy this puts life at danger. The code is a p002 and if you research it Mercedes is aware of this and is most likely a defective high pressure fuel pump problem that needs replacing but there have been no recalls. I have looked it up on you tube and has been on ongoing issue with no recalls as of yet. I am taking my car to dealer on 11/15/2021 for this issue which they will charge me for even though its a safety issue
Suspension, Service brakes, Fuel/propulsion system, Oct 6, 2021
The rear drivers side had a loud chunking/clanking noise while driving and the vehicle was unable to control and break when in motion. Driving was impossible as the breaking component was a total failure and car could not be controlled while traveling down 45-50mph zone. I reduced my speed to 20-25 mph by letting off on the gas to get better control of the car if breaking would need to be suddenly made. I relied on the shoulder to pull off if any sudden breaking was needed. The car was immediately take to be reviewed by a specialized Mercedes benz mechanic and further inspection proved that the rear subframe on the driver’s (left) side was corroded and broken. The connecting arms are rusted, corroded and rendered the car inoperative. I notified my insurance company as well as car manufacturers corporate office. I researched this issue further and discovered that this reoccurring issue with this make and model. There are a pheletera of recounting of this same issue on various message boards to validate the same issues and callouts I found. The car was taken to the dealership that it was purchased and further inspection showed that the left side subframe/ subframe arms were corroded with rust and broken. The brake lines and fuel tank were equally rusted and corroded. The service manager confirmed that this is defect of the car but it had been part of a recall. I had the car towed for 2nd opinion to another dealership service department to access the car and this callout further validated the corrosion and rust was wide spread and has rendered the car inoperable unless these damages were fixed.
Engine, Aug 26, 2021
I purchased this 2012 C250 Mercedes from Carmax of Waldorf on 04/26/2017, with 20,046 miles on it. I informed Carmax the engine light was on and the car was rattling at start. I also reported the oil dipstick was broken. When the car was returned, the dipstick was replaced, coolant light off and engine light was off; however, the rattling at start up continued. I reported the problem to Carmax several months later and they pretty much denied fault and went as far to say the car is just cold and does that at startup. For further protection I signed with carshield as my wife drives the car. The car's rattling continued at startup and eventually became difficult to start. I took it to Mercedes of Arlington, Virginia and they stated the timing gear and chain needed replacing. carshield reported back to me that it was a preexisting problem and wouldn't fix it. Meanwhile, we were stuck with a car we were paying on with no one taking the blame. Following research, I found that this is a recurring problem with the 2012 C250 model but there is no recall. I eventually paid approximately $5000 for the engine to be repaired as the engine failed. The engine is currently rattling again; with the engine light coming on constantly. this seems to be a common problem, however, with to consequences and accountability.
Suspension, Aug 25, 2021
The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving approximately 15-20 MPH, there was a rattling noise heard and the vehicle was pulling to the right. The vehicle was taken to the dealer and diagnosed that the rear subframe was rusted and had fractured. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure and opened a case. The contact was awaiting a call back from the case manager. The failure mileage was approximately 120,000.
Suspension, Structure, Aug 24, 2021
I was driving my 2012 Mercedes C250 through an intersection on 08/09/2021 when I first heard clunking noises in the rear of my vehicle. Every time I placed my foot on the brakes after that it continued to clunk until I took it to the Mercedes dealership for repair on 08/17/2021. The car had about 57,000 miles on it and was only nine years old, but the dealership said that the entire rear subframe of the vehicle had rusted and was close to completely separating from other parts of the vehicle. This was the first time I heard of any rusting in my vehicle, despite having the 2 rear tires replaced and alignment by the same place on 10/02/2020 (less than one year before). The service rep acknowledged that the car was well-maintained and that this was not due to any accident. This rusting was due to a manufacturing defect and has caused accidents in other Mercedes vehicles (https://www.carproblemzoo.com/mercedesbenz/c300/suspension-problems.php). It has resulted in recalls of rusted parts in both Europe (https://europe.autonews.com/article/19981026/ANE/810260839/mercedes-offers-guarantee-against-rust-for-30-years) and Canada (https://www.wheels.ca/news/mercedes-benz-recalling-vehicles-for-rust-problems/). Had I been travelling at a higher rate of speed when this piece failed, I could have been at risk of serious injury. This event occurred without any warning lamps or messages. The service for replacement and realignment was quoted at $4,358.71. Only after much argument did I receive a final bill of $3448.71. This was an unbelievable cost for replacing a part with a manufacturer defect. Mercedes headquarters tried to claim that the issue was due to exposure to snow and salt on the roads. This region rarely gets any snow. This lack of care for customer safety along with the fact that the dealership did not retain the part they removed from my vehicle after I had requested them to do so, left me realizing that Mercedes doesn't care about safety standards for their products.
Service brakes, Jul 19, 2021
Brakes failed to deploy, randomly, during recent trip; VERY DANGEROUS; pressed brakes, would NOT engage and car kept moving and would not stop; pushed car into P (Park) to stop moving; just completed a 225 mi trip from Chicago to Detroit Metro area traveling at speeds between 65-70 mph with no issue, all service on vehicle is and has been conducted via Mercedes authorized dealers, had vehicle in for service on morning of trip for overview and safety check prior to leaving and no known issues; after coming off freeway engaged brakes upon pulling into neighborhood and vehicle brakes failed completely-stopped engaging; NO NOTIFICATION; NO INDICATOR LIGHTS OR READ OUT OF ISSUES related to brakes was indicated on dashboard; had we been on the freeway at the time of incident coming off an exit ramp at high speed we would have suffered a grave result, brakes failed completely. THIS IS A DANGER and UNACCEPTABLE for this manufacturer; vehicle has been towed to dealership, is not drivable, and is currently being assessed. This has been widely reported on other sites, regarding this specific vehicle, Mercedes C250, my model year is 2012; I researched this issue, yesterday, to determine what could possibly have gone wrong as vehicle was not leaking fluids and NO indication of issues during recent diagnostics and safety check two days prior. Not having sufficient braking capability with NO warning or indication is DANGEROUS, a liability to manufacturer and should be investigated immediately. Thank you.
Suspension, Jul 7, 2021
The contact owns a 2012 Mercedes-Benz C300. The contact stated that while driving at various speeds, the vehicle would drift from the center in either direction without warning. After describing the symptoms to an independent mechanic, he was informed that the rear subframe might be corroded. Upon inspection, the contact discovered that the subframe had started to corrode which had caused the failure. The dealer was notified of the failure and informed him that they are aware of the failure however, there was no recall regarding the issue. The contact attempted to notify the manufacturer of the failure but was unsuccessful. The vehicle was not repaired. The failure mileage was approximately 80,000.
Engine, Jun 27, 2021, fire
2012 Mercedes C250 caught fire with no warning. Drove about 5 miles to the store and parked the car. A passerby said your car is on fire. Within minutes the entire front of the car was ablaze. The vehicle was towed to the city impound lot and has not been inspected by anyone.
Air bags, May 28, 2021
The contact owns a 2012 Mercedes-Benz C300. The contact stated that the driver’s side air bag warning light was illuminated. The contact took the vehicle to a certified mechanic who cleared the code. The failure recurred. The vehicle was not diagnosed nor repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 93,541.