Here is the demonstration of BMW MCU 5M48H read & write by R280 CAS4 programmer.
R280 CAS+ IN CIRCUIT Programmer read 5M48H eeprom
R280 BDM programmer correct EIS/CAS odometer
R280 BDM programmer write dumps to MCU
Cas4 programmer read MCU 5M48H
R280 programmer check EIS/CAS odometer
Done!