Components connected to the Car Communication Computer (CCC): Microphone
WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
To test the microphone, the CCC or Top HiFi amplifier issues a test tone that is received by the microphone. If a Top HiFi system is fitted, no tone can be issued directly by the CCC. In this case, the test tone is created by the Top HiFi amplifier.