GF82.85-P-2030CEA Audio Mode, Function
GF82.85-P-2030CEA Audio Mode, Function
- with CODE (525) MB Audio 50 APS radio
- with CODE (511) Audio 50 APS with DVD changer
Function requirements, general
^ Circuit 30g On or Circuit 15R On
^ Auto pilot system (APS) is authorized and working correctly
^ No fault in antenna system (radio function)
^ Data DVD/CD inserted
The circuit 15 status is sent by the electronic ignition lock control unit (N73) to the interior CAN (CAN B).
Audio mode, general
Following audio functions can be selected using the RADIO menu or the DISK menu
^ Radio mode function sequence (AM/FM)
^ Function sequence for audio DVD/CD as well as MP3 (on DVD/CD)
The following components are available for control of the audio system:
- Control buttons on radio with auto pilot system (A2/56)
- Audio/COMAND control panel (A40/9)
- Left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)
- Voice control system microphone (B25/7) (with code (511) Audio 50 APS incl. DVD changer)
On vehicles without code (810) Sound system, the audio signals are output directly by the radio with auto pilot system to the following speakers:
- Left front door speaker (H4/1)
- Right front door speaker (H4/2)
- Left rear door speaker (H4/3)
- Right rear door speaker (H4/4)
The audio signals on vehicles with code (810) Sound system are sent by the radio with auto pilot system over the Media Oriented System Transport (MOST) to the sound system amplifier (N40/3) and finally amplified. The audio signals are output directly by the sound system amplifier control unit to the following speakers:
- Left front door speaker
- Right front door speaker
- Left rear door speaker
- Right rear door speaker
- Center dashboard speaker (H4/27)
- Bass speaker (H4/29) (model 204.0/2)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/57)
On model 204.0 the right rear surround speaker is integrated into the bass speaker.
On model 204.9 the audio signal for the rear bass speaker (H4/38) runs from the sound system amplifier control unit to the rear bass speaker amplifier (N40/9) and from there via direct lines to the rear bass speaker.
The MOST subscribers can be activated when circuit 15R is Off by switching on the radio with auto pilot system.
Information on the currently set stations or played title is indicated in the instrument cluster (A1) and Audio/COMAND display (A40/8).
Radio mode function sequence (AM/FM)
The antennas in the rear window receive audio signals for the FM and AM (MW, LW, SW) radio frequency bands.
The following useful signals relevant for the radio reception are modulated onto these signals:
- Music signals
- Speech signals
- Data signals (e.g. traffic information)
The signals are transmitted via direct lines to the FM, AM and CL [ZV] antenna amplifier (A2/18) (model 204.0) or rear window antenna amplifier 1 (A2/71) (model 204.2/9) as well as to the rear window antenna FM antenna amplifier (A2/19). The antenna amplifiers filter the frequencies of the radio frequency bands out of the received signals and amplify them. The amplified signals are then transmitted over the coaxial lines to the integrated radio tuners of the radio with auto pilot system, demodulated and output over the speaker system.
The radio mode function (AM/FM) consists of the following subfunctions:
^ Function sequence, AM reception (MW, LW, SW)
^ Function sequence, FM reception (FM)
^ Function sequence, radio data system (RDS) reception
Function sequence, AM reception (MW, LW, SW)
For the MW, LW and SW radio frequency bands, the useful signals are broadcast using amplitude modulation.
The AM tuner integrated into the radio with auto pilot system demodulates these signals. In other words, it also separates the useful signals (audible frequencies) from the carrier signal (inaudible). The radio with auto pilot system also enables an additional automatic reception-specific changeover between the antenna amplifiers.
Function sequence, FM reception (FM)
In the FM radio frequency band, the useful signals are broadcast using frequency modulation. The FM double tuner integrated into the radio with auto pilot system demodulates these signals. In other words, it also separates the useful signals (audible frequencies) from the carrier signal (inaudible).
The radio with auto pilot system also enables an additional automatic reception-specific changeover between the antenna amplifiers.
Additional function prerequisites for RDS reception
^ RDS function activated
^ Radio stations also transmit additional digital information
Function sequence, RDS reception
As well as the normal radio program, many radio stations broadcast additional digital information such as station names, the program type (e.g. pop, culture, etc.) and traffic radio recognition. This information is evaluated by the radio and shown on the Audio/ COMAND display. For this purpose, it is necessary for the functions of the radio with automatic pilot system to be activated.
Function sequence, Audio CD
On vehicles with code (511) Audio 50 APS incl. DVD changer, a DVD changer is integrated into the radio with auto pilot system. On vehicles with code (525) Radio MB Audio 50 APS, a single DVD drive is installed in the radio with auto pilot system.
This enables audio CDs and audio DVDs to be played (even MP3 format). User guidance for controlling DVD/CD functionality and displaying supplemental information is carried out via the Audio/ COMAND display.
The audio signals are output over the speaker system.
The menu guidance for controlling the CD functionality (e.g. track selection) and for displaying supplemental information (e.g. title) is on the Audio/COMAND display.
