Volvo 2007 S80 Owner's Manual page 76

Thumb wheel for adjusting display and instrument lighting
Rear fog light
Front fog lights
Headlights/parking lights
Instrument lighting
Illumination of the display and instrument lights will vary, depending on ignition mode.
The display lighting is automatically subdued in darkness and the sensitivity is set with the thumb wheel
The intensity of the instrument lighting is adjusted with the thumb wheel.
High/low beam headlights
Low beams
When the engine is started, the low beams are activated automatically (daytime running lights) if the headlight control
is in position or
Daytime running lights can be deactivated by an authorized Volvo workshop.
NOTE
.
.