I WAS DRIVING ON THE FREEWAY AND THE VEHICLE STOPPED, ROLLED TO A STOP, AND WOULDN'T START UP AGAIN. THIS RESULTED IN A SERIOUS ACCIDENT. I PUSHED THE HAZARD BUTTON BUT THE OTHER DRIVERS ACCOUNT OF THE ACCIDENT WAS THAT THE LIGHTS WERE OFF. THE CAR HAD ITS EPB REPROGRAMMED AND SUB RELAY REPLACEMENT DONE ACCORDING TO THE DEALERSHIP. I HAD NO PRIOR PROBLEM WITH THE CAR STOPPING UNEXPECTEDLY. I WAS KNOCKED OUT BY THE ACCIDENT, SO I DIDN'T HAVE MUCH TIME TO SURMISE WHAT THE PROBLEM MAY HAVE BEEN. IT MUST HAVE BEEN LIKE 30 SECONDS FROM THE TIME IT STOPPED UNTIL WE WERE HIT BY 3 CARS AT FREEWAY SPEEDS.