2025 MERCEDES-BENZ Glc 350 E 4MATIC

My 2025 Mercedes-Benz GLC 350e displayed a “48V battery malfunction” warning on or about July 1, 2026, while the vehicle was less than one year old. The vehicle was taken to an authorized Mercedes-Benz dealership and remained there until approximately July 20. Mercedes-Benz USA became involved, and the dealership ultimately stated that the malfunction had been corrected through a software update. The 48V battery was not replaced. I have not received documentation clearly identifying the specific software update, campaign, operation number, underlying failure mechanism, or pre- and post-repair diagnostic results establishing that the reported malfunction was caused and resolved by software. I am therefore unable to determine whether the battery or another component of the 48V system was defective, or whether the warning was merely cleared. In late August, I also heard a new and pronounced whirring sound near the left-front area of the vehicle after charging. A different authorized dealership charged the high-voltage battery to 100%, attempted to reproduce the sound, and found no charging-system fault codes or abnormal noise. It characterized the sound as normal post-charge cooling operation and performed no repair. I am submitting this complaint because of the original 48V malfunction, the lack of documentation identifying exactly what failed and what software remedy was performed, and the possible relevance to a previously closed NHTSA investigation involving Mercedes-Benz battery-related concerns. Please associate this complaint with any applicable closed investigation and evaluate whether this incident constitutes additional relevant field evidence.