NHTSA Complaint #11616616 — 2022 RAM PROMASTER

While cruising at highway speed with adaptive cruise control enabled, the vehicle will incorrectly detect traffic/speed signs and will rapidly decelerate on a highway in traffic. I believe that the message that displays after detecting the new speed limit (improperly based on a sign other than a highway speed limit sign) without giving the option to reject using the "resume" button before. There is an option to disable traffic/speed sign detection, but that must be manually disabled in software every time the vehicle is re-started. Adjustment of the speed during adaptive cruise control based on traffic/speed signs should be disabled for safety. It's fine to have the speed limit displayed on the dash, but dangerous to have the vehicle adjust speed on its own without sufficient warning, or at all. I would like to request that RAM be directed to disable the software connection between traffic/speed sign detection and the adaptive cruise control so that, just like regular cruise control, the operator chooses the vehicle's speed. Note that this issue has happened many times since I've owned the vehicle, which was purchased as new, but I am now complaining to NHTSA because I experienced multiple incidents on my most recent trip that might have risked a rear-end collision from a vehicle following me when deceleration occurred.