2025 MERCEDES-BENZ AMG GLC43 4MATIC COUPE Complaints

The vehicle experienced a sudden loss of power while driving on the freeway. The check-engine light began flashing, and the car immediately stopped accelerating. I was in the fast lane at freeway speeds when the vehicle lost power, forcing me to activate my hazard lights and merge into the slow lane to avoid being hit by other vehicles. It felt like the engine was about to stall in traffic, creating a major safety risk to myself and others. Component that failed: The dealer confirmed a constant misfire in Cylinder #2, caused by a burned spark-plug electrode. The misfire was present almost continuously. All four spark plugs had to be replaced. The failure is available for inspection and is documented in the most recent work order. Safety risk: Yes. The loss of power happened suddenly at freeway speeds, almost causing an accident. I had to drive with hazard lights on and crawl to the slow lane to avoid a collision. Confirmed by dealer: Yes. Mercedes-Benz of Fresno reproduced and confirmed the misfire, performed diagnostics, inspected all cylinders, ran a compression test, verified the burned electrode, and documented the engine misfire on the repair invoice. Inspected by manufacturer/service center: Yes. This was inspected by the authorized Mercedes-Benz dealership technicians. The issue has occurred alongside ongoing electronic/driver-assistance malfunctions reported since early ownership. Warning lamps/messages prior to failure: Yes. The check-engine light was flashing right before the loss of power. Previous issues with drivability, acceleration hesitation, and electronic faults have occurred multiple times before this incident.

The contact owns a 2025 Mercedes-Benz AMG GLC43. The contact stated that while driving approximately 70 MPH, the message "Rear Axle Malfunction" was displayed, and the vehicle stalled. The vehicle was towed to the local dealer who diagnosed the vehicle with a rear axle software malfunction. The rear axle software was updated, and the vehicle was repaired; however, the failure reoccurred. The vehicle was not yet repaired. The manufacturer was notified of the failure. The failure mileage was 300.