NHTSA Complaint #11702177 — 2021 AUDI A6 ALLROAD

The car has traffic sign recognition and uses it for "predictive control" where the vehicle will read traffic signs and adjust the adaptive cruise control setting to based on road signs. It had previously been working well but a software update was recently performed under TSB 2074688/3 on November 6th, 2025 and problems have shown up. Specifically, the system is incorrectly reading signs and sometimes appearing to make signs up out of nowhere. This has resulted in the car slowing down quickly on highways and nearly causing a couple of rear-end collisions due to the unexpected and erratic braking at highway speeds. The car will be going back to the dealer to be looked at, however this is unsafe because other drivers aren't prepared for a car randomly slowing down in front of them while on the highway for no reason. The car is also available to be inspected if needed. The issues first appeared within a week of having the TSB performed and has happened a number of times since. The following incidents have occurred: * Once on Highway 10 heading North/West between Big Lake and Elk River MN; the car was set to 60mph and hallucinated a 15mph speed limit sign. There was no speed limit sign on the road at all when this happened. This resulted in a near rear-end collision with the car behind. * Two times while on Highway 35E Southbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads. Once resulted in a near rear-end collision with the car behind. * Two times while on Highway 35E Northbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads * Once on Highway 35W Northbound in the Minneapolis/St. Paul metro: 60mph to 40mph on clear roads This software update is dangerous and should be updated or recalled, especially since the car did not have any issues of the sort prior to the update being performed.