My 2009 W212.72 E550 is an ex-Japan car that has been reprogrammed for NZ with English voice recognition, local navigation, expanded radio reception, etc. This also included deactivating a Japanese legal requirement] for cars to have a loud warning chime that plays inside the car when reverse is selected, just in case the driver doesn't realise that the car is going backwards!

Following a system reset by an MB dealership, the infuriating and loud Japanese domestic market reversing chime was reactivated. It plays from what sounds like a hidden speaker inside of the dash on the driver's side whenever reverse is selected.

The MB dealership (NZ's largest) refuses to deactivate it, saying it's a factory feature. As an aside, they also quoted me $2,800 to repair a faulty secondary air injection system that I fixed with a new $19 relay! as well as trying to get my agreement to various other service rip-offs which were not required. Suffice it to say, they lost my business.

My questions are:
Does anyone know how to deactivate this chime function?
Can it be deactivated through the dealer's hidden command system or using my iCarsoft MB II scanner?

Thanks for any help you may be able to provide.