ECU not reachable

Hello, my Diva has today signaled ESP = off, ADR = off and ABS = off in the form of yellow lights of the corresponding control lamps. After reading out with VAG Com the error check DTC Memory appears in the Breakbooster ECU. If this error occurred in the past – it was enough to delete the error memory of the ECU 03 (ABS) and swollen everything was good. Now the problem: the ABS ECU (03) no longer appears and I can’t delete the error in Him anymore. what can I do? thank you