BAS/ESP light goes on and off. Sometimes its on when I start the car, sometimes it goes on when I am driving, sometimes it is off for several days, sometimes it is on for several days. I changed the brake light switch but the problem continues. Sometimes it goes on under braking but just as often it will go while driving along. My independent can't read the code and the dealer is far away. Can any tools access this system? Any ideas besides the brake light switch?