2026 MERCEDES-BENZ Gle 450 4MATIC

While driving on a limited-access highway at 65 mph with cruise control engaged, the vehicle unexpectedly reduced speed to 50 mph without any driver input under steady traffic and road conditions. No braking was applied by the driver, and no warnings or alerts were displayed prior to or during the speed reduction. Separately, the vehicle’s displayed speed-limit information was unstable during highway driving. The display repeatedly changed between the correct posted speed limit, a blank display, and “---” under consistent conditions, without changes in roadway, signage, or map context. This behavior was observed multiple times and was captured on video recording. The unexpected reduction in speed created a safety risk due to loss of speed relative to surrounding traffic.

I was driving in I75 highway south in Michigan and heading to Ohio. I had around 70 mil/hr ish speed and was trying to pass a commercial truck. I Just turned on rear window wiper to clean it and once it started to work, the vehicle had a very hard brake for a couple seconds which the my seat belt pushed me hard to the seat to avoid of my head to go forward to windshield. Fortunately it was very quick brake and didn’t caused any accident, but I was worried that it was repeated again and had a lot stress until I arrived at the destination. I am guessing probably either park brake was engaged without touching it(software or part issue) or the sensors for front and emergency collisions had the bad function.