car won't start, battery good. No sound will not turn over

I would inspect your starter, make sure that there is a trigger voltage going to the starter solenoid from your ignition switch.

I have a 2005 X3 . Had the same problem it was the ESW moduel . Which is the cars drive away proction system. If the Car computer doesn't sinc with the ESW it demobailizes the starter and the car wont start . It ran me around $700 to replace. But you won't know for sure until you take it to a bmw dealer its $120 for a complete reading of the cars falty codes . Good luck!

check for an open fuseable link in your starting circuit

Take to dealer and reset the ECU it's a security thing with BMW cost bout 110.00.