As I'm driving my breaks are coming on the break peddle goes all the way down

I had the same issue last month on my 2002 ML320. My brakes would randomly engage, but only at lower speeds (around 30 mph or so.) This is a very scary and dangerous issue. In my situation, it turned out to be a bad Yaw Turn Rate Sensor. This sensor is located under the gear shift and it effects the Electronic Stability Control system. Basically, when this part fails it sends bad data out that makes your car think that you are sliding/skidding out of control thus it initiates the brakes. I would take the car to a mechanic and have them pull the codes to be sure, but the ESP light has to do with the stability control of the car. Hope this helps.

The NHTSA opened an investigation several years ago into this as they had NUMEROUS reports of the exact same thing happening. They sent affected vehicles to MB for testing and supposedly they could not recreate the problem. After a few years of no injuries or fatalities reported, they closed the investigation without mandating a recall. It turns out to be the yaw rate sensor which is VERY costly to replace ($3,000 est.). After reading the report, I drive with both hands on the wheel of my 2001 ML320 most of the time now, hoping that it does not happen to me.