2023 Mercedes-Benz AMG C43 Owner Complaints

My vehicle developed a coolant warning during normal road use. I had not experienced any known collision, crash, or unusual impact. I brought the vehicle to an authorized Mercedes-Benz dealer for inspection. The dealer diagnosed the problem as: “Front low-temperature cooler replacement – impact damage causing leak.” The repair estimate was approximately $2,385. The failed component is the front low-temperature cooler located directly behind the lower front grille. Based on the location and design, the cooler appears to have limited protection from ordinary road debris. The dealer believes that external impact caused the cooler to leak. I am concerned that this may represent a design or durability issue because a critical cooling-system component appears vulnerable to relatively small road debris during normal driving. A puncture or leak in this component can result in coolant loss, warning messages, overheating, reduced vehicle operation, or potentially loss of propulsion if the vehicle continues to be driven before the driver realizes the severity of the leak. This is a significant safety concern because the failure can occur suddenly during normal highway or road use without a collision. A driver may be forced to stop unexpectedly or may continue driving with insufficient coolant, which could create a risk to the driver and other road users. I believe Mercedes-Benz should review whether the front low-temperature cooler has adequate protection from normal road debris and whether additional protective screening, grille protection, or a revised component design is needed. The issue has been confirmed by an authorized Mercedes-Benz dealer. The vehicle and damaged component should be available for inspection if requested. I am requesting that NHTSA review whether similar complaints exist and whether this condition may represent a broader safety-related design concern.

NHTSA ID

11766731

Incident

Sep 23, 2026

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 ID

11735812

Incident

May 5, 2026

The contact owns a 2023 Mercedes-Benz C43 AMG. While driving into a parking lot at a very slow speed, the braking system suddenly activated, and the vehicle shut off. After restarting the vehicle, the messages "Rear Axle Malfunction", "Active Braking System Limited" and "Inoperative" were displayed. The cause of the failure was not yet determined. The manufacturer and local dealer were notified of the failure. The failure mileage was 5,600.

NHTSA ID

11572056

Incident

Feb 15, 2024

Mileage

5,600 mi