Hey guys

I have a problem where my abs, asc, and brake lights stay on and remain on. I'm not really sure what caused the problem since all 3 lights have been on since I bought the car. I'm thinking it's a sensor issue and all 3 lights could be related. I doubt it is the ABS module. Any thoughts on which part it is (specific sensor that I should replace)? Should I just bring the car to a BMW dealership and let them run a diagnostics/fix the problem? That would probably be the most expensive way of fixing it, but I would love some input on what you guys think the problem might be. Any help is greatly appreciated!