51 21 150 Blocking, If Necessary Initializing, Car Key In Immobilizer Control Module
WARNING: This page is about a different car, the 2008 BMW Alpina and 2007 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Execution in diagnosis system: ->Service functions-> ->Body-> ->Locking and security functions-> ->Remote control key.