Collision Avoidance complaints by model year
Which parts fail
Components named in complaints (automatic emergency braking, adaptive cruise, lane keeping, backup camera).
Mileage when the problem started
What owners report
Within the first week of ownership (delivery on 1/15/24), the car's parking and/or front collision sensors started malfunctioning on a regular basis. The sensors repeatedly gave off false alerts when the car would approach intersections even though no obstacles were in front of, or behind, the car. The false alerts were quite startling and they consisted of loud alarms and warning images in both the driver's display and the car's heads up display. The repeated false alarms posed a significant safety hazard because they initially caused me to slam on the brakes risking a rear end collision. Once I realized the sensors were malfunctioning, I started to ignore them which is equally dangerous if a real collision needed to be averted. The car is currently in the service department, and it has been there for a total of 29 days thus far. …
The vehicle appears to have experienced a braking system malfunction, possibly involving the brake-by-wire system, electronic stability control (ESC), or unintended acceleration event. When the brake pedal was fully depressed, the car suddenly and uncontrollably accelerated forward into a cinder block wall. After the incident, it was observed that only the left-side tires left skid marks, indicating an apparent brake imbalance or failure on the right side. The vehicle is available for inspection upon request. My safety and the safety of others were severely compromised. My daughter and I were in the car during this and are extremely traumatized. Despite pressing the brake pedal, the vehicle accelerated forward and crashed into a cinder block wall, which could have resulted in serious injury or death had a person, pedestrian, or oncoming vehicle been in front. …
The contact owns a 2023 Mercedes-Benz C300. The contact stated that on occasion while driving at various speeds, the vehicle unexpectedly stopped without the brake pedal being depressed. There were no warning lights illuminated. The vehicle was diagnosed twice by the local dealer, and the contact was advised that the Forward Collision Avoidance sensors needed to be recalibrated; however, the failure persisted. The vehicle was taken back to the same dealer where the vehicle was inspected, and the contact was advised that further diagnostic tests were required to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 28,000. The VIN was not available.
The contact owns a 2023 Mercedes-Benz C300. The contact stated while driving 50 MPH with the Intelligent Cruise Control activated, with no other vehicles or objects nearby, the vehicle inadvertently slowed down. After restarting the vehicle, the vehicle returned to normal functionality but later displayed the following messages: "Active Emergency Stop Assist Currently Unavailable", and "Active Steering Assist Inoperable". The Forward Collision Avoidance warning light was illuminated. The vehicle was taken to the dealer but not yet diagnosed. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 6,000.
The contact owns a 2022 Mercedes-Benz C300. The contact stated that while driving approximately 40 MPH, the active brake assists erroneously activated, causing the vehicle to abruptly stop in the middle of the road, nearly causing a rear end collision by another vehicle. During the failure there were no vehicles or objects present in front of the vehicle to cause the active braking system to be activated. The vehicle was taken to the local dealer who was unable to determine the cause of the failure. The manufacturer was notified of the failure. The failure mileage was 4,500.
The contact owns a 2022 Mercedes-Benz C300. The contact stated while driving at unknown speeds, the active brake assist was not functioning properly. The brakes were applied without an object around the vehicle. There were no warning lights illuminated. The local dealer was contacted and scheduled an appointment. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 20,000.
The contact owns a 2020 Mercedes-Benz C300. The contact stated that suddenly the vehicle's sensors were illuminating and activating a warning stated that the sensors were defective. Many of the vehicle's sensors began to deactivate and malfunction. While reversing out of a parking space the rear view camera and sensor system failed causing the contact to crash into another vehicle. Both vehicles were damaged. A police report was filed. There were no injuries reported. The vehicle was not towed. The contact took the vehicle to a repair facility and stated that there was damage to the internal sensor and camera system. The contact took the vehicle to the dealer however the vehicle had not been diagnosed or repaired as of yet. The contact then received a recall notice NHTSA Campaign Number: 22V232000 (BACK OVER PREVENTION) however the VIN tool confirms remedy not yet available. …
The contact owns a 2020 Mercedes-Benz C300. The contact was reversing out of her driveway at 3 MPH, the contact was using her rearview camera. The contact stated that the image froze and she crashed into a parked vehicle with the rear passenger side bumper of her vehicle. The contacts bumper was scratched and dented. The other vehicle had sustained a large dent in the driver's side door. The contact stated no warning light was illuminated. The contact had taken the vehicle to a local repair and not a dealer or an independent mechanic. The vehicle had been repaired cosmetically. The manufacturer had not been informed of the failure. The contact had received the manufacturer recall letter and related the accident to NHTSA Campaign Number: 22V232000 (Back Over Prevention). The failure mileage was approximately 6500.
Related recalls (2)
Back over prevention › Display function
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018-2021 CLA-Class, GLE/GLS-Class, A-Class, C-Class, E-Class, E-Class Coupe/Convertible, GLA/GLB-Class, GLC-Class, and CLS-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details.
Remedy: Dealers will update the rearview camera software, free of charge. Owner notification letters were mailed July 15, 2022. Owners may contact MBUSA customer service at 1-800-367-6372.
Forward collision avoidance › Sensing system › Radar
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2019 C300 Cabrio, C300A Cabrio 4MATIC, C300 Coupe, C300 Coupe 4MATIC, C300, C300 4MATIC, C43 AMG Cabrio 4MATIC, C43 AMG Coupe 4MATIC, C43 AMG 4MATIC, C63 AMG Cabrio, C63S AMG Cabrio, C63 AMG Coupe, C63S AMG Coupe, C63 AMG, C63S AMG, CLS450, CLS450 4MATIC, CLS53 AMG 4MATIC,…
Remedy: MBUSA will notify owners, and dealers will update the radar sensor control unit software, free of charge. The recall began September 13, 2019. Owners may contact MBUSA customer service at 1-800-367-6372.
Frequently asked questions
Which Mercedes-Benz C300 years have collision avoidance problems?
By NHTSA complaints, the 2015 (11), 2023 (10), 2022 (9), 2020 (6) and 2018 (5) model years. Collision Avoidance complaints make up 3% of all complaints for the 2015.
Is there a recall for Mercedes-Benz C300 collision avoidance problems?
Yes — 2 recalls, including 22V-232 (display function, Apr 8, 2022); 19V-540 (radar, Jul 19, 2019). Recall repairs are free at authorized dealers; check a specific car with the VIN recall check.
At what mileage do Mercedes-Benz C300 collision avoidance problems start?
Across all years, half of the complaints with a recorded mileage happened before about 14,000 miles; 93% happened before 50,000 miles.
What part fails most often?
Owners most often name the warnings (24 mentions), followed by the automatic emergency braking (23).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.