Launch X431 X-Prog3 PC Adapter user feedback:
Read Audi- Q8 MD1CP004 success
Run X-PROG3 PC software, select Audi>> Q8 2018-2019>> MDCP004 SPC5777
Check the wiring diagram
Need to connect 1-VCC, 10-GND, 8-1GN2, 6-CANL, 9-CANH cables
Connect X431 PC Adapter to X-Prog3 and ECU
Also connect to computer properly
Then read and save eeprom and flash data separately
X-prog3 also can correct checksum for MD1 ECU.