AW: The signal from the light switch (‘Illu signal’ wire on the ISO wiring harness) of the vehicle is used to control the display brightness.
The screen brightness mode can also be adjusted from the ‘Auto’ setting to permanent ‘Day’ or ‘Night’ mode.
The display brightness can be fine-tuned by calling up the app list and then select ‘Settings’ -> ‘TFT screen’.
Also see chapter ‘TFT screen settings’ in the device operating instructions on page 53.