What changes
Module 5F (MIB3): 0550 byte 7 bit 3 = 1, 0551 byte 0 bits 3 and 2 = 1. Signature sound on start-up and the 'heartbeat' when you leave.
Details
The function_configuration_audio → welcome_sound and function_configuration_sound → vehicle_readiness_sound, vehicle_leaving_sound adaptations. Enabled on a Chinese 2023 Q3 F3 (MIB3, software 3801/3853) — both sounds work. The MIB2+ has only the welcome sound and none of these objects. MIB3 only (from model year 2021): the MIB2+ (MH2p, 2019–2020) has no such object, and Odyx refuses before writing. If module 5F is SFD-protected (Q3 F3 from model year 2021), Odyx asks for a token; some Chinese MIB3 units have no SFD — then no token is needed. The MMI restarts after writing. Rollback: write the object backups from the history.