Les dejo esta info para los que tienen la OBC de 18 botones! Son funciones ocultas que no están dentro de las que vienen por defecto de fábrica.
Por ejemplo lectura de voltaje en tiempo real, cantidad de litros en tanque de combustible, velocidad actual Km/h Mph, ETA(estimated time of arrival), cambiar lenguaje,etc

To determine if your OBC is eligible .. press 1000 and 10 together.
you should see TEST NO . -- or something like that.
Now, some of the functions are locked out -- I do NOT recommend messing with them and you do so at your own risk -- that said ...
To unlock all functions .. press 1000 and 10 and at the TEST prompt enter 19 using the keys .. press SET/RES .. you should see LOCK:ON or something similar ... press the DATE key .. (today you'd see 01.24) and add the two numbers (day and month) together (today 24)

Now enter the number you just calculated and press SET/RES. TADA .. you have unlocked the secret functions ...

To lock them back up .. press 1000 and 10 then enter 19, SET/RES now press SET/RES again .. it should show .. LOCK:ON again

In general when I show a test enter it by pressing 1000 and 10 together then enter the number of the test with the numeric keys and press SET/RES to actually execute the test ...

Test numbers for E36 OBC
Test no. Description
1 Display Test .. all LCDs and LEDs activate
2 Current Consumption in l/100km
3 Current Consumption in l/hour
4 Average Consumption (used to calc. Range)
5 Current Range
6 Not used ..
7 Average Fuel in Tank (l)
8 Current Speed (km/h)
9 System Voltage at terminal R
10 Country/Language
11 Units/ AM.PM
12 Average Speed (km/h) for calc. ETA
13 ETA
14 Date of software/mask of OBC
15 Production Diagnosis (??)
16 Production Diagnosis (??)
17 Display Vehicle Specific Data
18 Alarm Changeover (continuous v. intermittent)
19 LOCK/UNLOCK all functions
20 Correction Factor for OBC Fuel Consumption (SEE BELOW!)
21 Reset all defect codes, date and time ... activate by pressing SET/RES

Acá dejo un link con lo mismo y funciones ocultas en el tablero de instrumentos
http://www.bmwe36blog.com/bmw-on-board- … crets.html