The car went from 20 miles an hour and 35 miles an hour (happened 2 times) to a sudden hault like hitting a wall. The first time I had to restart the car. The second car, I had to return it to drive. A big X came up on the dashboard. I have owned the car 17 months. Both issues happened in the last 30 days. Nothing beefore. The car has 4415 miles on it. The dealer (Fletcher Jones) was unable to replicate). There was no warning. They told us it was our problem and we could report it to Mercedes Benz which we will do today.

Source: NHTSA complaint ODI #11759874 · view all complaints for this vehicle at nhtsa.gov

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.

Source: NHTSA complaint ODI #11761658 · view all complaints for this vehicle at nhtsa.gov

Suspension exhibits excessive bounce/instability over road irregularities, unsafe on uneven pavement, affects steering control. Car available for inspection. Checked by two authorized dealerships, both closed as "operating as designed" without resolving it. Also inspected by manufacturer's Field Service Engineer, same result. Issue began after a phantom braking event — vehicle braked suddenly and unexpectedly on its own while changing lanes at highway speed, no obstruction present, no driver error — also damaged the steering column, since replaced.

Source: NHTSA complaint ODI #11747605 · view all complaints for this vehicle at nhtsa.gov

The contact owns a 2025 Mercedes-Benz GLC350E 4MATIC. The contact stated that while driving at 68 MPH, the sunroof glass shattered unexpectedly. The contact was able to pull over, and the vehicle was towed to the nearest dealer. The dealer had not yet diagnosed the vehicle. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 17,500.

Source: NHTSA complaint ODI #11750300 · view all complaints for this vehicle at nhtsa.gov