All BMW 3series cars of the E90, E91, E92 (and probably E93) family have hidden/service menus in the Board Computer (BC)
Although on cars with iDrive, some of this information can be accessed in a more readable format through the hidden iDrive menus
Accessing the menus
To access these hidden menus (or service menus), you have 2 options..
Turn ignition on, or start your car
Press and hold the button to reset the daytrip/odometer for 10 seconds
Press and hold the button to reset the daytrip/odometer
While keeping this button pressed, insert the keyfob into its slot, and release the button
At this point the BC should display data in a "XX.YY" format. So if the BC displays "01.00", that means Main Menu 01, sub menu 00
To continue to navigate the menus, you need to use again the daytrip/odometer button (hereafter just called 'button')
For more information go to this site.