I have recently purchased an OEM Android Auto unit from China for my ML 350 W166 2013. On connecting it everything works well except the reverse camera video. I have the original MB camera still connected. It powers up and shows the reverse guide lines but there is no pic when i engage reverse. The vendor says i must buy a camera from him to have that function but i think there's one more step to make the reverse camera work since it's already powered without changing or drilling holes to add an OEM camera. Just need the video signal to show.
Any help or suggested wiring to complete the setup