00 00... Battery: check display (magic eye); if necessary, recharge battery
WARNING: This page is about a different car, the 2006 BMW X5, 2005 BMW X5, and 2004 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
For further information on how to proceed, refer to GENERAL ELECTRICAL SYSTEM - X5 (4.4L) .