Apr 23, 2026Transmission & drivetrainElectrical systemEngine
Vehicle has ongoing and recurring electrical and engine-related defects that affect safe operation. The primary systems involved are the electrical system, engine ignition system, and powertrain. The vehicle is available for inspection upon request. Prior service records show issues beginning in 2020 involving repeated electronic system failures requiring multiple repairs and component replacements. Since purchasing the vehicle in April 2023, the vehicle has developed more serious failures, including: – September 2024: Check engine light with loss of power and inability to exceed safe driving speeds – October 2024: Engine misfiring due to ignition coil failure requiring replacement of ignition components – September 2025: Additional ignition coil electrical fault (code P0353) The problem has been reproduced and confirmed through dealership service inspections and diagnostic reports. Warning indicators, including the check engine light, appeared prior to failure events. These defects create a safety risk due to potential loss of power, engine failure, and unreliable vehicle operation while driving, which could increase the risk of an accident. The issues have required multiple repairs without permanent resolution and appear to be ongoing and worsening over time.
NHTSA ODI 11733212
Apr 3, 2026Electrical system
Car stops accelerating and shifts into neutral without warning I nearly got hit from behind. I have consulted several other Mercedes vehicle owners and all had the same issue. Two of the other owners stated that this happened on the interstate and was very lucky they were not involved in a collision. Both vehicles were GLC 300. Mercedes does not seem to have an answer to the issue and all previous owners traded vehicles for fear of dying.
NHTSA ODI 11729030
Jan 11, 2026Electrical systemBrakesDriver assistance
points: ⸻ While driving, the vehicle displays the warning “Active Brake Assist Functions Limited – See Operator’s Manual.” The message appears during normal driving and does not go away. This warning indicates that the automatic emergency braking / Active Brake Assist system is limited or disabled, reducing a critical safety feature designed to help prevent or mitigate collisions. This creates a safety risk because the vehicle may not automatically brake in an emergency situation. The warning appeared suddenly while driving, with no visible obstructions, weather conditions, or damage to sensors. Restarting the vehicle does not consistently clear the message. The issue has not yet been inspected by a dealer or repair facility. The cause of the malfunction is UNKNOWN, and the vehicle is available for inspection.
NHTSA ODI 11710171
May 25, 2021Electrical systemCrash
The contact owns a 2020 Mercedes-Benz C300. The contact stated that her son was driving at an undisclosed speed when another vehicle's muffler detached and crashed into the undercarriage of the contact's vehicle. The front driver and passenger side tires exploded and fractured the rims. The contact stated that the vehicle's alert system failed to warn her son of the incoming object which resulted in the collision. The contact's son did not receive medical attention. A police report was filed. The vehicle was towed to the dealer and repaired. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was 6,000.
NHTSA ODI 11418528