This car has the driver assistance package including Active Speed Limit Assist which is supposed to automatically adjust the speed of the vehicle based on detected speed limits. However, it gets the speed limit wrong an excessive amount of the time sometimes resulting in the car suddenly decelerating which I consider to be a serious safety issue that could result in collisions. In my situation, I have experienced the car suddenly slowing to 40 mph for no reason in an area where the speed limit was 65 mph. I have also seen this problem documented on a number of blogs related to Mercedes-Benz vehicles. When I reported the problem to the dealership, I was told that it was a known issue and was encouraged to turn this feature off. I think Mercedes-Benz needs to fix this known issue for those of us who have cars with Active Speed Limit Assist.

Source: NHTSA complaint ODI #11612912 · view all complaints for this vehicle at nhtsa.gov

The electrical wiring harness of my vehicle completely caught fire making my vehicle stopped working. Manufacture warranty refuses to acknowledge this as an ongoning issue with this models and forcing me to pay for my own repairs this is a danger to anyone driving this vehicle as the car entirely can be caught on fire at any given time.

Source: NHTSA complaint ODI #11596594 · view all complaints for this vehicle at nhtsa.gov

I am filing a safety complaint regarding my 2023 Mercedes-Benz AMG C43 4MATIC. The vehicle has approximately 23,000 miles. On multiple occasions, the vehicle has abruptly and violently applied the brakes and/or come to a near stop while I was driving on highways and side roads, even though there was nothing in front of me that should have triggered emergency braking. There was no vehicle, pedestrian, cyclist, object, or road hazard present that would justify this braking event. This is not normal braking behavior. The car essentially performs an uncommanded emergency stop or severe deceleration without warning. The force is strong enough to create a serious risk of being rear-ended by vehicles behind me. This has happened at highway speeds and on local roads, making the vehicle unsafe to operate. If a following driver is unable to react in time, this defect could easily cause a crash, injury, or death. The problem appears related to the vehicle’s automatic emergency braking / Active Brake Assist / forward collision avoidance system and possibly other linked driver-assistance systems. The vehicle has already been serviced on two separate occasions for this exact issue, yet the problem has occurred again. Despite bringing the vehicle in for repair more than once, the defect remains unresolved. Because this dangerous unintended braking continues to happen, I cannot continue to drive the car safely with this issue unresolved. On April 1, 2025, I took the vehicle to Aristocrat Motors in Merriam, Kansas for the car slamming on the brakes and beeping when no one was around. The service center calibrated the augmented reality camera and performed a test drive. The invoice indicates that they were unable to duplicate the braking event during the test drive. They ran codes with SDS and found that the augmented reality camera was not calibrated correctly, so they performed a calibration. On December 31, 2025, I again took the vehicle to Aristocrat Motors in Merriam, Kansa

Source: NHTSA complaint ODI #11735812 · view all complaints for this vehicle at nhtsa.gov

2 of 245/40HR18XL & 2 of 225/45HR18XL... All 4 tires replaced I purchased a 2023 Mercedes-Benz C300 from Benzel Busch motor car (an authorized Mercedes-Benz dealer) in [XXX] in XXX. Since purchase, this vehicle has had repeated, unresolved defects. The Check Engine warning light has illuminated numurous times, resulting 4 separate towing incidents. Despite multiple warranty repairs, the same issues keep recurring. At only 10,167 miles, one tire required replacement due to abnormal wear. At only 22,780 miles, all 4 tires required full replacement for the same reason. In total 5 tires have been replaced within 22,780 miles, strongly suggesting an underlying vehicle defect (alignment, suspension or steering) rather then normal wear. I paid $1,700 out of picket for the 22,780 miles tire replacement, as tires are not typically covered under warranty. I believe this cost resulted directly from an unresolved vehicle defect, not drive behavior. I filed a formal complaint with Mercedes-Benz USA Customer Assistance Center and received Case No. XXX. I was told reimbursement would not be provided. Desired Resolution: Reimbursement of $1,700 for the tire replacement caused by an unresolved vehicle defect, and a written explanation of how Mercedes-Benz USA will address the recurring mechanical issues. Supporting docyments available: Repair orders, tire receipt, email correspondence. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Source: NHTSA complaint ODI #11744607 · view all complaints for this vehicle at nhtsa.gov

When going into Reverse the passenger side mirror angles down to see curbs. When putting back into Drive it should be going back up to normal angle, but 20% of the time it does not go back up. If you're driving in the dark you may not know it's reverted back up and get into a car accident. Dealership said there are no issues and a technician stated it goes back up at +9 mph. I've gone over 30 mph driving on public street only to realize it late. I am hoping this gets publicity before an accident occurs due to a defective safety-comfort feature.

Source: NHTSA complaint ODI #11699593 · view all complaints for this vehicle at nhtsa.gov