2012 Mercedes-Benz C300 Problems & Complaints

Most common 2012 Mercedes-Benz C300 problems

• Air bags~53,000 miles
  11443%
• Suspension~121,000 miles
  6926%
• Body & structure~110,000 miles
  5420%
• Other / not specified
  239%
• Brakes~110,000 miles
  156%
• Fuel & propulsion system~96,000 miles
  125%
• Electrical system~85,000 miles
  125%
• Steering~92,000 miles
  83%
• Engine & cooling~53,000 miles
  52%
• Transmission & drivetrain~88,000 miles
  52%
• Wheels & tires~100,000 miles
  42%
• Lights~80,000 miles
  42%
• Windows, wipers & sunroof~169,000 miles
  31%
• Speed control & acceleration~40,000 miles
  10%
• Seat belts~66,000 miles
  10%
• Stability & traction control
  10%

Share of the 266 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.

Mercedes-Benz C300 complaints by model year

Best C300 years: 2014, 2021, 2020. Years to avoid: 2009, 2008. Compare all years →

2012 Mercedes-Benz C300 recalls (6)

NHTSA defect investigations

Federal safety investigators have looked into a possible defect involving the 2012 Mercedes-Benz C300:

What 2012 Mercedes-Benz C300 owners say

Air bags all 114 →

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.

I was driving normally last week when the driver's head restraint system (known by Mercedes as Neck Pro) unexpectedly and without warning blew at my head. The noise was very loud, and the headrest slammed against my head. Luckily, I was driving approximately 20-25 miles per hour, daytime, on a residential street without too many other vehicles. I was able to pull over to investigate what happened and ensure I wasn't injured and did not collide with any objects in the road. If this had happened on the highway at highway speeds with a less attentive driver, I could see this potentially resulting in a major collision. The road was fat, no bumps, weather was clear. There is no reason why this happened. From what I can tell, the system looks like it failed (plastic clips broke off) and the system did not intentionally deploy. It has not been repaired and is available for inspection. …

Suspension all 69 →

I ran off the road and my rear suspension sub frame literally broke in half. Upon further research I've learned that these parts are faulty and several people have had theirs rust completely in two. Mine had lots of rust damage and that is likely what caused the damage to mine when I ran off the road (MINOR impact that should have never caused that much damage). Mercedes has recalled this part in several countries including Germany and Canada. When I drove home after running off the road my car was nearly impossible to drive. It was jerking all over the road and when I tapped the brakes the rear end of the car would come up off of the road (into the air)! This was in June. It's now September and I still have not been able to obtain a part from Mercedes. So many people are having this issue with their vehicles that the part is on back order until Q1 of 2023. …

The contact owns a 2012 Mercedes-Benz C300. The contact stated while driving 70 MPH, there was an abnormally loud sound from the rear of the vehicle. The contact lost control of the vehicle. There was no warning light illuminated. The contact was able to continue normal driving once he regained control of the vehicle. The contact scheduled an appointment with an independent mechanic for the vehicle to be inspected. The contact was informed that the rear subframe had detached from the passenger's side of the vehicle due to severe corrosion. The dealer was notified of the failure and informed him that there were no recalls related to the failure on his vehicle. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 138,000.

Body & structure all 54 →

The contact owns a 2012 Mercedes Benz C300. The contact stated that while driving 45 MPH, the contact started to lose control of the vehicle while depressing the brake pedal. There was no warning light illuminated. The contact regained control of the vehicle and drove to a dealer. The vehicle was inspected, and the mechanic discovered that the subframe had fractured due to severe corrosion. The contact was notified that the vehicle was unsafe to drive. The contact was provided an estimate for the repair. The manufacturer was also notified of the failure and informed her that 15% of the cost of the repair would be covered. The vehicle was not repaired. The failure mileage was approximately 62,000. The contact stated that their vehicle was finally repaired by the dealer in Dec. 2022. The manufacturer helped pay approximately 13% of the total repair costs.

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.