MARCH 14,2018 DRIVING AT APPROXIMATELY 15-20 MPH IN A RESIDENTIAL NEIGHBORHOOD,APPROACHING A RAILROAD TRACK, VEHICLE SUDDENLY CAME TO AN ABRUPT STOP. BRAKE COLLISION MITIGATION FLASHED ON DASH. SCREEN INSTRUCTIONS TO PLACE VEHICLE IN PARK. I TURNED ON EMERGENCY FLASHERS FOR SAFETY. ONCE IN PARK AND RETURNED TO DRIVE, ABLE TO CONTINUE. MY RIGHT ANKLE SPRAINED DUE TO FORCE OF STOP WHILE PRESSING ON ACCELERATOR. MY TEEN IN THE BACK SEAT SUFFERED WHIPLASH. THANKFULLY NO CAR IMMEDIATELY BEHIND US. SINCE THIS TIME, I TURN OFF THE COLLISION BRAKE MITIGATION EACH TIME I START THE VEHICLE. FEARFUL OF THE SAME ACTION OCCURRING AGAIN! DEALERSHIP HAS RUN DIAGNOSTICS BUT HAS NO SOLUTION! NO ACCIDENT REPORT FILED.