Volvo 2008 C30 Owner's Manual page 93

Press the right side of the button: the interior courtesy lighting stays off.
Courtesy lighting - automatic function
The interior lighting has a built-in automatic function that switches on the courtesy lighting for 30 seconds when:
the vehicle is unlocked from the outside using the key or remote control
the engine is switched off and the ignition key is turned to the 0 position.
The courtesy lighting lights up or remains on for 5 minutes when:
one of the doors is opened and left open.
the courtesy lighting has not been switched off (the right side of button 2 depressed).
The automatic lighting goes out when:
the engine is started
the vehicle is locked from the outside using the key or remote control.
If the courtesy lighting is not switched off manually, it will be turned off automatically 5 minutes after the engine has
been switched off.
Rear lighting
The cargo area lighting consists of a light on the driver's side of the cargo area.
The courtesy lighting and cargo area lighting illuminate when the rear liftgate is opened, and remain on for 5 minutes.
The lighting is turned off when:
the rear liftgate is closed
if button 2 is put in position 0 (off).
103
04 Interior
Interior lighting
Vanity mirror