Instrument panel lighting
The instrument panel lighting illuminates when
the ignition key is in position II and the light
switch (1) is in either position 
Move the thumb wheel (4) up to increase brightness or down to decrease brightness.
See also:
How do states use OBD II for emission inspections?
Many states connect a computer directly to a
vehicle's OBD II system. The inspector can
then read "faults." In some states, this type of
inspection has replaced the tailpipe emission
...
Selecting a sound source
• Press AM/FM (4) repeatedly to toggle
between FM1, FM2, and AM
• Press the CD button (1) to change to the
CD player or optional CD changer
• Turn the SELECTOR control (5) to choose
FM1, FM2, AM, ...
MY CAR
When the MY CAR symbol has been selected,
the following menu alternatives are displayed.
• My XC60
• Support systems
• Settings ...