Using Scan Tool
WARNING: This page is about a different car, the 1995 Audi A6. However, it is still accessible from the selected car via links, so may be relevant.
Enter self-diagnostics. See ENTERING SELF-DIAGNOSTICS . Select function "05", ERASE DTC MEMORY. If DTC MEMORY IS ERASED is displayed, press right arrow button until prompted to select another function. If DTC MEMORY HAS NOT BEEN READ is displayed, read DTC memory again. See RETRIEVING CODES . Select function "05" again to erase DTC memory.