NHTSA complaint #11545369

Owner complaint summary

While driving at speed (about 45 mph) in moving traffic. The nearest car in front was a out 4-5 car lengths ahead. Without warning the Auto-Breaking system activated and immediately slammed on the breaks to slow the car losing about 20 mph before I was able to press on the gas to get it going again. I had to accelerate very quickly to avoid being hit from the rear as there was no reason for the car to brake and so no other vehicles on the road were slowing as all traffic was moving together through an intersection. There was a slight bump in the road as there is in intersections of crossing multi lane roads, but nothing that would require a normal slowdown. The weather was clear... no rain or fog or dust etc. This was unsafe for there was no reason for the car to brake. This made it all the more startling. Also it was dangerous because it put me at risk for a rear end impact since again there was nothing to require a breaking action no objects or slowing traffic ahead. There were no specific warnings or issues beforehand as for this system. The car has had its "radar / optical" based systems error message pop up saying the system was inoperative, but this was during rainy driving on somewhat dirty roads, so it was assumed this inop-mode was due to debris on the external sensors ... however as stated during the auto breaking incident it was a clear day with no weather. We have not reported this to the dealer yet but will mention it next service. No outside agencies have inspected the car at this time since we did not get into an accident however that was very possible if someone was not paying attention behind me.