Automatic adaptation of display brightness

The automatic adaptation of display brightness prevents major sudden changes in the brightness of the head-up display when the vehicle moves between different ambient lighting conditions (e.g. from light to dark and from dark to light when driving through a tunnel).

The automatic adjustment of the display brightness depends on

• the ambient lighting conditions,
• the brightness adjustment setting,
• the dimmer setting for instrument lighting (only when the lights are on).

The surrounding brightness (day, night, twilight, sunshine, etc.) is recorded by the rain/light sensor. The value of the brightness adjustment (difference between base setting and individually set display brightness) is stored in the headup display. When the lighting is switched on (terminal 58g, lights ON) the brightness of the head-up display is also influenced by the dimmer setting of the instrument lighting.