It's called Emergency Brake Assist. It's in the owner's manual. Basically, it's another nanny that is supposed to keep us from dying. What it does is sense the force and speed in which you apply the brakes. In an event like you describe it assumes you are trying to avoid a crash, which you were. It keeps the brakes applied for a couple of reasons. First, even though ABS brakes have been around a long time, there are still driver's out that that have never experienced ABS in action. The common reaction when the brake pedal starts to pulsate is it scares the driver, and they lift off the brake causing a crash anyway. The Brake assist takes this into account and keeps the brakes applied briefly to make sure you don't really want to stop. The other thing that it does is apply 100% of all available braking force at that moment. Some people can't/don't push the pedal hard enough, so if the pedal is hit hard and quickly, it takes that as a panic stop and applies 100% of the braking force weither you push the pedal 100% or only 80%. I hope that makes sense. I saw a video on it when I worked at the Chrysler Dodge dealer a couple of years back. I can see why it would alarm you if you didn't know the feature was there, but I think it's pretty cool...