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..

Option 1

1. Turn ignition on, or start your car
2. Press and hold the button to reset the daytrip/odometer for 10 seconds

Option 2

1. Press and hold the button to reset the daytrip/odometer
2. 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')

• While the display reads XX.__ press the button repeatedly to select the main menu option (XX)
• when reaching the desired main menu option, wait for 2 second for the display to read XX.00, at this time pressing the button will select the sub menu (YY)
• To go back to selection of a main menu (XX), press and hold the button for 2 seconds, until it shows XX.__ again.
  
• To leave the hidden/service menus press and hold the button for 10 seconds, or remove the keyfob.

At this point, the available main menus are 01, 02 and 19. To access the remaining menus a code is required.
This code can be found under menu 01.00 and needs to be calculated as follows from the Chassis number
Say the number displayed is XX12345, you take the last 5 digits (12345 in this case), and add them all up, so 1+2+3+4+5=15. Meaning your unlock code is 15.

To enter the unlock code, go to main menu 19, and wait until it asks for the unlock code. Now press the button until it reads your unlock code (15 in our example), and the display will show 'lock: off'.
Now all menus are available

Menu list and description

Note: please make corrections/additions to this list if you have additional information!

Menu	German text	English Translation	Notes	Picture
01.00	FGSTNR (Fahrzeug ?? Nummer)	Vehicle ?? number
01.01	K-ZAHL W/T (Kilo-Zahl Wirklich/Tacho?)	Tacho in thousands True/Tacho?
01.02	BMWTNR (BMW Teilenummer)	BMW Part number of Instrument panel?
01.03	COD DIA	Diagnostic code?
01.04	KI HSTLDATUM (Kombi Instrument Herstellungs datum)	Instrument Panel Manufacturing date
01.05	HW AEI	Hardware revision ??	First part is probably the hardware revision of the instrument panel. Unclear what the second part (AEI is)
01.06	SW	Software version?
01.07	KODIERDATEN	Coding data
01.08	CAN	Can Bus version?	Should this not be Most-Bus instead? (but isn't there still a CAN bus even thought there's also a MOST bus?)
02.00	KI TEST (Kombi Instrument Test)	Instrument Panel Test	When the display shows 02.00, click the button one more time to start the test. Causes all indicator to light up, and gauges to go to max.
03.00	UNBELEGT	Unused	On some older cars (pre-E90), this menu contains service data, but not anymore.
04.00	VERB-MOM (Verbrauch im Moment)	Current fuel consumption in l/100km
04.01	VERB-MOM (Verbrauch im Moment)	Current fuel consumption in l/hour
04.02	D-VERB1 LIT (Durchschnitt Verbrauch im Liter?)	Averages - Consumed fuel
04.03	D-VERB1 WEG (Durchschnitt Verbrauch im Wegstrecke?)	Averages - Distance traveled
04.04	D-VERB2 LIT (Durchschnitt Verbrauch im Liter?)	Averages - Consumed fuel in Liters
04.05	D-VERB2 WEG (Durchschnitt Verbrauch im Wegstrecke?)	Averages - Distance traveled
05.00	RW-VERB (Reichweite Verbrauch)	Range Fuel usage	This is used to calculate how much further you can drive
05.01	RW-MOM (Reichweite im Moment)	Estimated range until tank is empty
06.00	TANK L R S (Tank Links Rechts Summe)	Remaining fuel in left and right fuel tank, and total (Left-Right-Sum)
06.01	TANK-ANZ PH	Total fuel tank content	why is this different from the 06.00 total value? and what is the trailing 'PH' value (1 in this case)?
06.02	TANK-OHM L R	prehaps the resistance values returned by the left and right fuel level sensors? that is, the 'raw' data from which the calculated values in litres are calculated
07.00	KTMP-MOM (Kühlmittel Temperatur im Moment)	Current Coolant temperature
07.01	ATMP-MOM (Außen Temperatur im Moment)	Current Outside temperature
07.02	ATMP ADC (Außentemperatur Analog Digital Converter)	Raw temperature value from analog digital converter
07.03	N-MOT-MOM	current engine revs per minute
07.04	N-VWF-MOM	revs per minute limit on M cars whilst engine warming up (increase in blocks of 50rpm as temp rises)
08.00	V-EFF	Current speed
08.01	V-ANZ	Speed shown on indicator
08.02	V-SZ	Cruise control speed on indicator
08.03	DGESCH1 WEG	?? - Distance traveled
08.04	DGESCH1 ZEIT	Total Time driven?
08.05	DGESCH2 WEG	?? - Distance traveled
08.06	DGESCH2 ZEIT	Total Time driven?
09.00	UB	Voltage
10.00	KM / WOCHE	KM/Week
10.01	GELB CBS H A	?
10.02	SC-STATUS	?
10.03	CBS-MODE	?
10.04	TAG-ZAEHLER (Tag Zähler)	Day Counter
11.00	ZEIT-EINH (Zeit Einheit)	Time format	12 or 24
11.01	WEG-EINH (Wegstrecke Einheit)	Distance format	KM or MLS
11.02	TEMP-EINH (Temperatur Einheit)	Temperature format	°C or °F
11.03	VERB-EINH (Verbrauch Einheit)	Fuel Usage format	l/100km, km/l or mpg
12.00	V-ANKUNFT (Veranschlagt Ankunft?)	Estimated ?? until arrival
12.01	ANK-ZEIT (Ankunft Zeit)	Estimated Arrival time
13.00	AUDIO	Sound test	Press button to play BLINKER, ACC Gong, CCG and DG sounds
14.00	FS-EINTRAEGE (Fehler Speicher Einträge)	Memory error entries
14.01	FSP01 (Fehler Speicher Position 01)	Memory Error Entry 01
14.02	FSP02 (Fehler Speicher Position 02)	Memory Error Entry 02
14.03	FSP03 (Fehler Speicher Position 03)	Memory Error Entry 03
14.04	FSP04 (Fehler Speicher Position 04)	Memory Error Entry 04
14.05	FSP05 (Fehler Speicher Position 05)	Memory Error Entry 05
14.06	FSP06 (Fehler Speicher Position 06)	Memory Error Entry 06
14.07	FSP07 (Fehler Speicher Position 07)	Memory Error Entry 07
14.08	FSP08 (Fehler Speicher Position 08)	Memory Error Entry 08
14.09	FSP09 (Fehler Speicher Position 09)	Memory Error Entry 09
14.10	FSP10 (Fehler Speicher Position 10)	Memory Error Entry 10
15.00	PORT 00h	?
15.01	PORT 01h	?
15.02	PORT 02h	?
15.03	PORT 03h	?
15.04	PORT 04h	?
15.05	PORT 05h	?
15.06	PORT 06h	?
15.07	PORT 07h	?
15.08	PORT 08h	?
15.09	PORT 09h	?
15.10	PORT 0Ah	?
15.11	PORT 0Bh	?
16.00	DIMMRAD CAN	Dashboard lighting?
16.01	PHOTO-ADC	Day light measurement
16.02	DIMM-PWM SZ	?
16.03	DIMM-PWM DK	?
17.00	DISP-HEIZ	Display heater on/off
17.01	NCT1 NCT2	?
17.02	KONTR-PWM	?
18.00	CC-TEST	Check Control Test
19.00	UNLOCK	Unlock menu
20.00	KORR-VERBR	Correction factor - Usage	Korrekturfaktor Verbrauchsanzeige Fuel consumption correction factor
20.01	1ER KORR	1st correction?	Change the 'ones' digit of the correction factor
20.02	10ER KORR	10th correction?	Change the 'tens' digit of the correction factor
20.03	100ER KORR	100th correction?	Change the 'hundreds' digit of the correction factor
21.00	RESET?	Software reset