Battery Disconnect Procedure: Notes
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2006 BMW M3, 2005 BMW M3, 2004 BMW M3, 2003 BMW M3, and 2002 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If ignition is not turned off when battery is disconnected, fault memories may be set in some control units.