I cant remember but I think you need to scroll to the "unlock" before you can do the reset.
To access the hidden BMW Service Menu;
1) Put the key in the ignition.
2) Press and hold the trip reset button. *ABS light comes on then goes out, keep holding the button in.
3) When the hidden service menu appears in the instrument binnacle, press trip button several times until option 19 'unlocking' is selected, then press and hold.
4) Tap until the number that is the cumulative number of the last 5 digits of the vehicle VIN added together (in my case 10) is shown, then press and hold to unlock menu.
5) Select desired option by pressing trip button, then access item by holding button in.
6) 'System Test' shows all dashboard symbols and graphics (quite cool!)
7)*To exit service menu, press and hold trip button from main menu.