It can be part of the canbus depending on how the car is wired as the signal wire for illumination can be via canbusI come back to your question about the lighting of the symbols on the left. This has little to do with Canbus, it's a setting....
go to Settings - General - Backlight Control -off
and now the backlight works when you turn on the light.
Settings - General - Backlight Control - on
now you can adjust the backlight according to the clock, e.g. 1900h - 0600h