On our 2007 X3, after replacing the battery I had a light on the dash, can't remember if it was the 4x4 light or a different one. I reset the steering angle sensor by turning the wheel lock to lock, and it went out. No other resetting was required.

Jeff

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue