What 25 owners told NHTSA about the 2023 Mercedes-benz C-class Phev

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

NHTSA ODI 11735812

On 4 different occasions car brake assist activated causing car to come to an immediate stop and jerk. At stop light as I started to accelerate a left turn car came to an immediate stop almost causing the car behind hit rear end. Brake assist light activated. This happened twice. And twice when in reverse backing out of a parking space and backing into driveway. Dealership notified look at my car and stated they did not see anything wrong. 4th incident happened within 30 minutes after leaving Wilmington Mercedes Benz.

NHTSA ODI 11674663

On 2/17/24 the vehicle was parked in front of my house. There is a slight grade. The vehicle had been parked for approximately 1 hour when my neighbor called me to tell me that the vehicle had rolled down the hill and into his storage building. The vehicle rolled on its own. I have video evidence that no one was in or around the car at the time of this occurrence. I also, have 2 eyewitnesses who can corroborate this story. Due to safety concerns, I immediately returned the vehicle to Mercedes. I have .MOV files and pictures JPEG that will not upload for some reason.

NHTSA ODI 11577612

The Mercedes just slams on the brakes for no reason. It's happened 3x and is very scary. According to Internet posts this is a common problem because of collision assist malfunction

NHTSA ODI 11528225

First week, the car would take off fast as soon as the brakes were released. Then first time I used the heat there was a crackling sound coming form the side of the center display and it got extremely hot, I was on the FWY driving in the rain. Brakes: Intermittently, when braking, the car speeds up as if shifting to N, problematic in the FWY traffic behind another car, sometimes the brake pedal can be heard rattling really lose underfoot, brakes also used to groan when backing up. Electrical: intermittently, the door/trunk lock, side mirror, garage door opener do not work, and the dash displays change by themselves, the worst is the unreasonably hot center display that burns fingers, and becomes untouchable on hot days. Transmission: seems not to work in unison with the accelerator as sometimes the RPM needle hits 3-4 but the car will not speed up or is sluggish. Other: the car intermittently kicks, like being rear ended, it happens at different speeds and stopped or driving, continuing a few times intermittently for a day or two. Twice have taken the car to MBZ dealership, one for 2 days, another for 10 days, they said they reset everything and all was fine. The issues are intermittent and hard to duplicate for some one who does not drive the car regularly. The dealership has been great but I do not feel they are able to reveal the problems with the vehicle. The car is like a computer with a virus and sometime gives erratic response.

NHTSA ODI 11523001

The contact owns a 2023 Mercedes C300. The contact stated that while traveling over a pedestrian crosswalk, the emergency braking mode was engaged. The accelerator pedal was applied but the vehicle failed to accelerate. The vehicle went into restricted mode. A Hyundai Elantra crashed into the rear of the vehicle. The driver in the Hyundai stated that the brake lights were not illuminated. There was no air bag deployment or fire. A police report was filed. The contact who was occupying the front passenger seat sustained an injury to her neck and medical attention was provided. The vehicle was towed to the local dealer where it was diagnosed that there were no restricted mode codes located. They were unable to duplicate or verify the incident. The vehicle was not repaired. The manufacturer was contacted but no additional assistance was provided. The failure mileage was approximately 2000.

NHTSA ODI 11520942