I have seen this many times. I get these phone calls daily. I have an X3 in here right now for that same reason. He's an engineer, yay, and a YouTube fanatic also. What a gem. He told me he had some warning lamps on, (SRS, 4X4, Brake, and Light bulb), and they all came on at the same time. Sure they did? Dealer to him he needed a steering angle sensor, DSC module, Heater Control Unit, and a passenger occupancy sensor, vehicle had no heat, and all the bulbs are working. Dealer told him it may have communication issues? Something definitely didn't sound right to me. He brought the vehicle to me. We went through the diagnosis. It had multiple faults in many systems. So, I decided to drill him a little, and found out the lamps did come on at different times. Also, he told me intermit. his low coolant lamp comes on. One of these days people are going to take responsibility of their ignorance.
What we found out:
1.) Needs a steering angle sensor (took care of his Christmas Tree dashboard)
2.) Needs a HALO bulb
3.) Needs a coolant expansion tank - coolant was way low and leaking externally! Not a control assembly.
4.) His valve cover was puking oil!
Thank you dealer. He bought everything. It just took a little extra time.