Hello everyone,

I am sharing this information in case anyone else encounters the same problem and is looking for a solution in the future.

My mother's 2018 xDrive30i had absolutely no issues with driving, and all accessories were functioning normally. However, after replacing the injectors, when we tried to read error codes from all the vehicle's modules to reset the adaptation, we were unable to read the DME (Digital Engine Management System). We tried using several diagnostic tools, but they all displayed the message "Cannot connect to DME," and the DME did not appear in the list of modules to scan.

At first, we thought it was a fuse issue, but it was strange that the other modules were reading normally. We checked the OBD fuse for the BDC (Body Control Center) and found no issues, and we inspected the wiring as well, but found no problems. At the time, ISTA (Internet Diagnostics) was unavailable (though it is now), so we eventually gave up and took the car to a repair shop. The interesting thing is that ISTA also indicated that several other modules were not communicating.

With BMW headquarters providing assistance and guidance on the inspection points throughout the entire process, the diagnosis took about three and a half weeks. It was eventually determined to be a faulty BDC (Brake Distribution Sensor), so I replaced it, and everything is now back to normal. For reference, the diagnostic cost was approximately $750, and the BDC replacement cost was about $2,000. It ended up costing quite a lot despite being a minor functional issue. I inquired if I could purchase the BDC and code it myself, but BMW told me they would send it to me already pre-coded. In other words, this means I won't be able to replace it myself if a similar problem arises again in the future. Phew, the world is really something these days... haha.