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Home >> Mercedes Benz >> 2012 >> E 63 AMG Sedan (212.074) V8-5.5L Turbo (157.981) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> GF82.85-P-2030FL Audio Mode, Function

GF82.85-P-2030FL Audio Mode, Function



GF82.85-P-2030FL Audio Mode, Function
- with CODE (512) COMAND APS with DVD changer
- with CODE (527) COMAND APS with single DVD drive (with navigation)
- with CODE (528) COMAND with DVD changer
- except CODE (498) Japan version


Function requirements
^ Circuit 30g ON

General information on the audio mode
Audio functions are operated using the following components:
- Left multifunction steering wheel button group (S110)
- Group of buttons on right of multifunction steering wheel (S111)
- Audio/COMAND control panel (A40/9)
- Function keys of the COMAND controller unit (A40/3)

In vehicles with code (810) Sound system, the audio signals are output by the COMAND controller unit via Media Oriented System Transport (MOST) to the sound system amplifier control unit (N40/3) and from there via direct lines to the following speakers:
- Center dashboard speaker (H4/27)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/55) (with model 212.2)
- Right rear surround speaker (H4/57) (with model 212.0)
- Left front door sound system tweeter (H4/68)
- Right front door sound system tweeter (H4/69)
- Left rear door sound system tweeter (H4/70)
- Right rear door sound system tweeter (H4/71)
- Left front door sound system midrange and bass speakers (H4/72)
- Right front door sound system midrange and bass speakers (H4/73)
- Left rear door sound system midrange speaker (H4/80)
- Right rear door sound system midrange speaker (H4/81)

For the bass speaker (H4/17) (model 212.0) or for the bass speaker (H4/29) (model 212.2), the audio signal is routed from the COMAND controller unit to the sound system amplifier control unit via MOST and from there to the bass speaker via the rear bass speaker amplifier (N40/9) using direct lines.

On vehicles without code (810) Sound system, the audio signals are output over direct lines by the COMAND controller unit to the following speakers:
- Left front door speaker (H4/1)
- Left front door tweeter (H4/1h1)
- Right front door speaker (H4/2)
- Right front door tweeter (H4/2h1)
- Left rear door speaker (H4/3)
- Left rear door tweeter (H4/3h1)
- Right rear door speaker (H4/4)
- Right rear door tweeter (H4/4h1)

The audio mode consists of the following function sequences which can be activated with the "Audio" menu item
^ Function sequence for radio mode function (FM/AM)
^ Function sequence for DVD/CD audio and video
^ Function sequence for Bluetooth(R) audio (as of 1.6.2010)
^ Music Register, general (except code (528) COMAND with DVD changer)

Further subfunctions are described in separate documents:
^ Digital Audio Broadcasting (Digital Radio) (DAB) (with code (537) Digital radio)
^ Satellite Digital Audio Radio (satellite radio) (SDAR) (with code (536) SIRIUS satellite radio)
^ Media Interface (with code (518) Media Interface)

Function sequence for radio mode function (FM/AM)
The antennas in the rear window receive signals for the FM and AM (SW, MW and LW) 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 received by the antenna structure in the rear window.

The signals are sent over direct lines to the FM 1, AM, CL [ZV], and KEYLESS-GO antenna amplifier (A2/18) and to the FM 2 and DAB antenna amplifier (A2/19). These amplifiers filter the frequencies of the radio frequency bands out of the received signals and amplify them. The amplified signals are then sent via coaxial lines to the tuner integrated in the COMAND controller unit and demodulated.
The demodulated audio signals on vehicles with code (810) Sound system are sent by the COMAND controller unit via MOST to the sound system amplifier control unit, where they are amplified.

The radio mode function sequence consists of the following subfunctions:
^ Function sequence for AM tuner (MW, LW, SW)
^ FM double tuner function sequence with phase diversity (FM)
^ Function sequence for Radio Broadcast Data System (RBDS) (with code (494) USA version) or radio data system (RDS)
^ Function sequence for Radiotext+ (as of 1.6.2010)
^ Function sequence for high-definition (HD) radio mode (with code (494) USA version)

Function sequence for AM tuner (MW, LW, SW)
For the MW and LW radio frequency bands, the useful signals are broadcast using amplitude modulation (AM). These signals are demodulated by the AM tuner integrated into the COMAND controller unit. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).

FM double tuner function sequence with phase diversity (FM)
For the FM radio frequency band, the useful signals are broadcast using frequency modulation (FM).

These signals are demodulated by the FM tuner integrated into the COMAND controller unit. In other words, it also separates the useful signals (audible frequencies) from the carrier signal (inaudible). The COMAND controller unit also enables reception- specific switchover between the FM 1, AM, CL [ZV], and KEYLESS-GO antenna amplifier and the FM 2 and DAB antenna amplifier.

Function sequence for RBDS (with code (494) USA version) or RDS
In addition to the normal radio program, many FM radio stations also transmit additional digital information such as station names, program type (PTY) (e.g. pop, culture, etc.) and traffic program identification.
This information is evaluated by the COMAND controller unit and shown on the Audio/COMAND display (A40/8), when the following preconditions are complied with:
- An RDS or RBDS station is set.
- The "RDS or RBDS" function is activated.

Function sequence for Radiotext+ (as of 1.6.2010)
During FM radio operation, additional information on the program can be shown on the Audio/COMAND display. For this, the "Info" softkey in the function bar must be pressed.

Function sequence for HD radio mode (with code (494) USA version)
The HD radio function is implemented in the COMAND controller unit. The integrated HD tuner is a combined AM/FM/Weatherband (WB) receiver with HD radio function. It demodulates the analog AM and FM signals using the two integrated double tuners and decodes the digital AM and FM signals using the integrated HD radio decoder chips.
The "Weatherband" function allows reception of US "Weatherband" signals. The HD radio function also allows additional reception of digital carrier waves for analog AM/FM programs, which are also broadcast by the stations.

The HD radio function improves the audio quality using digital technology:
- FM (96 kBit/s):
- CD sound quality (no "multipath interferences")
- AM (36 kBit/s):
- FM sound quality (stereo)

The stations also broadcast other audio channels and data with the digital carriers. This supplements the program with up to 2 additional audio channels per frequency (e.g. foreign language program from "National Public Radio") and supplemental information (e.g. track and artist) can be received.
Additional transmission of digital carriers is designated as "On Channel", the digital station is tuned to the same frequency as the analog station. The digital transmission process in the FM and AM band is known as "in-band".

In contrast to the satellite digital audio radio (satellite radio) (SDAR) function (with code (536) SIRIUS satellite radio) regional stations and programs are received by the HD radio function and no fees will be charged

Function sequence for DVD/CD audio and video
The DVD/CD audio and video function can be used to play audio CDs or audio DVDs (including MP3 format) as well as video DVDs. User guidance for controlling DVD/CD functionality and displaying supplemental information is carried out via the Audio/COMAND display. Data exchange between the COMAND controller unit and the Audio/COMAND display is performed via the telematics CAN (CAN A).

As of 1.6.2010, the artist name will also be shown on the Audio/COMAND display if the CD provides the information.

The video signals are sent via a low voltage differential signal (LVDS) line. For vehicles with code (810) Sound system, data exchange takes place between the COMAND controller unit and the sound system amplifier control unit over MOST. The audio is output by the following speakers via direct lines:
- Center instrument panel speaker
- Left rear surround speaker
- Right rear surround speaker
- Left front door sound system tweeter
- Right front door sound system tweeter
- Left rear door sound system tweeter
- Right rear door sound system tweeter
- Left front door sound system midrange and bass speakers
- Right front door sound system midrange and bass speakers
- Left rear door sound system midrange speaker
- Right rear door sound system midrange speaker

On the bass speaker, the audio signal is routed from the COMAND controller unit to the sound system amplifier control unit via MOST and from there via the rear bass speaker amplifier using direct lines to the bass speaker.

On vehicles without code (810) Sound system, the audio signals are output over direct lines by the COMAND controller unit to the following speakers:
- Left front door speaker
- Left front door tweeter
- Right front door speaker
- Right front door tweeter
- Left rear door speaker
- Left rear door tweeter
- Right rear door speaker
- Right rear door tweeter

Function sequence for Bluetooth(R) audio (as of 1.6.2010)
Via the Bluetooth antenna (A2/91), the COMAND controller unit can receive Bluetooth(R) audio signals from external devices. Bluetooth(R) audio is divided into the following subfunctions:
^ Search for devices and authorization
^ Connection and reconnection
^ Meta data and display of information

Search for devices and authorization
The same options exist for the authorization of a Bluetooth(R) audio source as are available for telephony:
- Search via the device list or
- External authorization

The device lists are set up the same for Bluetooth(R) audio and telephony. In the respective list, only those devices that support the corresponding Bluetooth(R) profile of the respective function are found or displayed during a search.

During telephony, the hands-free profile (HFP) is used. With Bluetooth(R) audio, the Audio/Video Remote Control Profile (AVRCP) and Advanced Audio Distribution Profile (A2DP) are used. If a device supports both functions, it is shown in both lists following authorization.

Connection and reconnection
An authorized device can be connected by means of selection in the corresponding list. If a device is connected that supports both HFP and AVRCP and A2DP, all profiles are connected. That means that the device is now a telephone and at the same time a source for Bluetooth(R) audio. On most devices, it is necessary to start the player on the telephone so that it can then be controlled via the COMAND controller unit.

When starting, the COMAND controller unit proceeds with the following strategy: First a check is performed as to whether an authorized telephone is inserted in the mobile phone cradle (A34/15) (with code (386) Comfort telephony).

If this is the case, the COMAND controller unit connects to the telephone and assumes the comfort telephony status.
If a mobile phone cradle (with code (386) Comfort telephony) is present but no telephone is inserted, a prompt appears after 2 min as to whether a switchover to basic telephony is desired. With "No", the system remains in the comfort telephony status. If no mobile phone cradle is present, the COMAND controller unit searches for the last two telephones. If one of these devices is found, the COMAND controller unit connects to this device. If this device also supports AVRCP and A2DP, these profiles are also connected. If a device is connected that only supports HFP and it is changed to the Bluetooth(R) audio application, "No Bluetooth audio device connected" is shown on the Audio/COMAND display if the corresponding audio sources are shown in the device list.

With the comfort telephony status, the connected device is always treated as if it only supports HFP.

If no Bluetooth(R) audio source is shown in the device list, "No Bluetooth audio device authorized" is shown on the Audio/ COMAND display and the selection option "Connect last device" is not shown in the menu.
If a Bluetooth(R) audio source is shown in the device list, the last Bluetooth(R) audio source used can be connected via "Connect last device". However, the connection to the current telephone is interrupted here.

The search process with "Connect last device" can only be interrupted by changing to telephony. Otherwise, the search is continued in the background.

If a device is connected that only supports AVRCP and A2DP and a change to telephony is then made, the connection to the device is disconnected and the COMAND controller unit begins the search for the last two telephones.

Meta data and display of information
The display of information for Bluetooth(R) audio depends on the respective device used. If this supports AVRCP 1.0, "Audio streaming" is exclusively shown on the Audio/COMAND display and in the instrument cluster (A1).
As of AVRCP 1.3, the track, album and artist are shown. In addition, the currently played time of the track can also be conveyed. Furthermore, there is the option of changing between the normal track sequence and shuffle.

It is possible to jump to the next or the previous track using the left multifunction steering wheel button group.

Notes on supported devices for Bluetooth(R) audio can be found.

Music Register, general (except code (528) COMAND with DVD changer)
On the integrated hard drive in the COMAND controller unit, files (in the MP3 format) from a CD/DVD or a Personal Computer Memory Card International Association (PCMCIA) card can be stored and then called up again as and when required.





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