00 00 ... Checking horn, headlight flashers and hazard warning system: Horn
WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
Check function.
NOTE:
In the case of twin-tone fanfares, make sure that both fanfares are working properly.