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:
Driving Impressions
The gentle but capable XC90 is solid and refined and handles more like a taut
European sedan. It reacts masterfully on twisting roads and functions with
precise control.
Expect a smooth and soli ...
Indicator, information, and warning symbols
Indicator and warning symbols
1 - High beam and turn signal indicators
2 - Indicator and warning symbols
3 - Information symbols
4 - Indicator and warning symbols ...
Heated oxygen sensors
The heated oxygen sensors monitor the oxygen content of the exhaust gases. Readings
are fed into a control module that continuously monitors engine functions and controls
fuel injection. The ratio ...