BMW F18 5 series was commonly seen the failure, oil measure not possible, use the scanner or BMW diagnostic tool read the fault code is: CD9304-BSD communication fault. and the fault code can not be deleted. First step is to check the cables, exclude to cables failure. measure the BSD data line voltage. If all the cables in good condition, check the DME. If confirmed the DME failure, it can be repaired, And it' the Continental DME MSV90 common fault.
Should be very careful to open the ECU, I have to say this ECU shell is very tough to open, especially the back side, and very easy to damaged the inner circuit board. Most people damaged the inner board via open it, and the damage can not be repaired, so must be extremely careful and slowly with lots of patient.
