Welcome to Bimmerefest.
I think you need to specify the model and year, sometimes we need the mileage. Then get a BMW OBD scanner, if you don't have scanner yet, go to a auto parts supply (store) for tools loaner. Take note of the codes and provide us. Make sure you have to reset the fault codes and observe if they reappear. Also, what kind of problem you observe with the car, what are the parts you replaced to fix it or previously replaced. If you already started troubleshooting, provide in detail what were procedures you did so far.