MOST Bus Diagnosis: Audio

WARNING: This page does not describe the selected car, but rather 59 other vehicles, including the 2009 BMW M5, 2009 BMW 650i, 2009 BMW 550i, 2008 BMW M5, and 2008 BMW 760Li. However, it is still accessible from the selected car via links, so may be relevant.

The two models E60 and E65 differ considerably in the area of the audio systems. These design differences necessitate different assessment methods for the purpose of locating faults.

The ASK is responsible for audio output on the E65. If the vehicle is equipped with a Top Hi-Fi amplifier, the audio signal is sent in the form of a light signal from the audio source to the Top Hi-Fi amplifier and forwarded to the speakers as an electrical signal.

Some of the speakers are activated directly by the ASK and some by the Top Hi-Fi amplifier (LOGIC 7).

If the E65 is equipped with a Hi-Fi amplifier, the sound information is transferred via a hard wire circuit to the amplifier.

In connection with the Top Hi-Fi system on the E60, all sound signals are routed from the multi-audio system controller/car communication computer in the form of light signals to the Top Hi-Fi amplifier.

No sound signals are transmitted along fibre-optic cables in connection with the stereo and Hi-Fi systems. The multi-audio system controller/car communication computer itself is responsible for the control of the speakers.