Originally Posted by bchuong58
"Active faults: 2E7C: bit serial-data interface, signal".
The diagnostic message shows you that this is bit serial-data interface has bad connection, the cable connector is bad or not connected properly, this is not programming issue. It can't communicate to electric coolant pump, intelligent battery sensor signal,
DME master relay, oil condition sensor, alternator etc, because it can't read the data from this serial data interface. The dealer pulled this connector out and did not reconnect it for you.
By installing a "good" water pump, all the faults cleared. Weird... according to the BMW technician, the communication works in a loop, if there is a faulty component in that loop the car go nuts and triggers a bunch of other faults.
Does that sound right?