Audio Mode, Function - GF82.85-P-2030GN
Model 166 as of model year 2016
Model 292
Shown on model 292
Illustration shows model 166
Function requirements, audio mode, general
- Circuit 30g ON
- Transport mode not active
General information on the audio mode
The audio mode consists of the following component functions:
- Function sequence for volume/tone settings
- Function sequence for radio operation (FM, AM, HD radio)
- Function sequence for digital radio (DAB) (with CODE 537 (Digital radio (DAB)))
- Function sequence for Satellite Digital Audio Radio Service (SDARS) (with code 536 (SIRIUS satellite radio))
- Function sequence for DVD, CD audio
- Function sequence, multimedia connection unit
- Function sequence for SD card (Secure Digital) (with code 522 (Audio 20 radio) or with code 531 (COMAND APS))
- Function sequence, storing audio CDs on the COMAND controller unit (with CODE 531 (COMAND APS) and CODE 494 (USA version) or with CODE 498 (Japan version))
- Function sequence for Bluetooth® audio
The audio mode can be operated using the following controls:
- Buttons on audio equipment
- Left multifunction steering wheel button group
- Right multifunction steering wheel button group
- Audio/COMAND control panel
- Touchpad (with CODE 531 (COMAND APS))
- Voice control system (with code 531 (COMAND APS)), by way of the hands-free system microphone group
Menu guidance and the display of additional information are carried out on the Audio/COMAND display. The Audio/COMAND display is switched on by the audio equipment via telematics CAN. The picture signals are received by the Audio/COMAND display over the low voltage differential signaling line from the audio equipment.
On vehicles except CODE 810 (Sound system) and CODE 811 (Advanced sound system), the audio equipment outputs the audio signals via the vehicle's speaker system.
On vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the audio signals are forwarded via the MOST to the sound system amplifier control unit, which then actuates the speaker system.
Function sequence for volume/tone settings
All volume and tone settings are performed using the audio equipment. This is performed either by the user or automatically by the audio unit.
The sound settings can be changed with "Tone" and the system returned to the default settings in the system settings menu.
On vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the audio equipment is equipped with additional tone settings along with the generally available ones (treble, bass and balance).
The volume and tone setting partial function is subdivided into the following subfunctions:
- Function sequence for manual volume/sound settings
- Function sequence for speed-dependent volume control (SDV [GAL])
Function sequence for manual volume/sound settings
The manual volume/tone setting function is subdivided into the following subfunctions:
- Function sequence for volume settings via right multifunction steering wheel button group
- Function sequence for volume settings through the audio equipment
- Function sequence for sound settings via audio/COMAND control panel
- Function sequence for tone settings using touchpad (with CODE 531 (COMAND APS))
On vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the desired settings are forwarded via MOST to the sound system amplifier control unit where they are processed. On vehicles except CODE 810 (Sound system) or CODE 811 (Advanced sound system), the selected settings are processed in the audio equipment. The audio output over the speaker system can be interrupted using the mute function button of the right multifunction steering wheel button group or using a button on the audio equipment.
Function sequence for volume settings via right multifunction steering wheel button group
The volume for the audio and video sources is increased or decreased by pressing the + and - buttons, selecting specific functions and volume control. The control signals are forwarded as follows:
Steering wheel electronics →
Steering LIN →
Steering column tube module control unit →
Chassis CAN 1 →
Electronic ignition lock control unit →
Chassis CAN 2 →
Instrument cluster →
Interior CAN →
Audio unit
Function sequence for volume settings through the audio equipment
Turning the control on the audio equipment increases or reduces the volume.
Function sequence for sound settings via audio/COMAND control panel
The user can set the corresponding sound by selecting the "Sound" menu on the audio/COMAND control panel.
The Audio/COMAND control panel control signals are transmitted via the telematics CAN to the audio equipment.
Function sequence for tone settings using touchpad (with CODE 531 (COMAND APS))
The user can make the corresponding tone settings by selecting the "Sound" menu on the touchpad. The touchpad control signals are forwarded via the telematics CAN to the COMAND controller unit.
Function sequence for speed-dependent volume control (SDV [GAL])
The volume is adapted to the noise level in the vehicle interior using the speed-dependent volume control, which is defined by the vehicle speed.
In order to make this adjustment, the instrument cluster sends vehicle speed information to the audio equipment via interior CAN. In vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the audio equipment forwards the information via MOST to the sound system amplifier control unit. In accordance with this information the audio equipment or the sound system amplifier control unit raises the output level or lowers it.
On vehicles with CODE 811 (Advanced sound system), the SDV is additionally optimized by using the sound system microphone. The sound system amplifier control unit reads in the signals of the sound system microphone, evaluates the signals, and adjusts the volume of the audio signals to the interior or driving noises.
Function sequence for radio operation (FM, AM, HD radio)
The antennas receive signals for the frequency bands FM (ultra-short wave) and AM (medium wave) and - not available in all national versions - short wave (SW)). 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 FM-1 signals are received via direct lines via the following route: Rear window antenna (model 292) or rear spoiler antenna (model 166) →
FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier →
Audio unit
The FM-2 signals are received via direct lines via the following route: Rear window antenna →
FM 2 and DAB antenna amplifier (model 292) or FM 2, DAB and TV antenna amplifier (model 166) →
Audio unit
The AM signals are received via direct lines via the following route: Rear window antenna (model 292) or rear spoiler antenna (model 166) →
FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier →
Audio unit
The radio mode function sequence consists of the following subfunctions:
- AM tuner function sequence
- Function sequence, FM twin tuner with multipath reception
- Function sequence for Radio Broadcast Data System (RBDS) (with CODE 494 (USA version)) or Radio Data System (RDS) (except CODE 494 (USA version), except CODE 498 (Japan version))
- Function sequence, HD radio (with CODE 494 (USA version))
AM tuner function sequence
For the MW and LW radio frequency bands, the useful signals are broadcast using amplitude modulation (AM). The AM tuner integrated into the audio equipment demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).
LW signals are not received by all national versions.
Function sequence, FM twin tuner with multipath reception
For the FM radio frequency band, the useful signals are broadcast using frequency modulation (FM).
The dual FM tuner integrated into the audio equipment demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible). The audio equipment integrates the signals from the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier and from the FM 2 and DAB (model 292) antenna amplifier or the FM 2, DAB and TV antenna amplifier (model 166) into an optimized signal (phase diversity).
An additional tuner function is integrated into the audio equipment for additional information such as the weather band or the FM multiplexer for the Vehicle Information and Communication System (VICS).
Function sequence for Radio Broadcast Data System (RBDS) (with CODE 494 (USA version)) or Radio Data System (RDS) (except CODE 494 (USA version), except CODE 498 (Japan version))
In addition to the radio program, many radio stations (FM) also broadcast additional digital information such as station name and traffic message channel recognition.
The additional digital information is evaluated by the audio equipment and shown on the Audio/COMAND display, provided that the following preconditions are complied with:
- An RDS or RBDS station is set.
- The "RDS or RBDS" function is activated.
Function sequence, HD radio (with CODE 494 (USA version))
The HDTV tuner integrated into the audio equipment decodes the digital signals. Additional information and services are shown on the Audio/COMAND display, e.g. Program Service Data, Artist Experience, traffic information.
Function sequence for digital radio (DAB) (with CODE 537 (Digital radio (DAB)))
The tuner unit permits the reception of digital radio in DAB format. With DAB, the stations are categorized into groups known as "Ensembles". Control of the DAB functions is accomplished via the audio equipment. The information or displays required for control are shown on the Audio/COMAND display.
On model 292, a DAB band III signal (DAB 1) is received via the following route:
Rear window antenna →
FM 2 and DAB antenna amplifier →
Tuner unit
On model 292, an additional DAB band III signal (DAB 2) is received via the following route:
Rear window antenna →
TV 2 antenna amplifier →
In model 166, the DAB 1 signal is received via the following route:
Rear window antenna →
FM 2, DAB and TV antenna amplifier
TV and DAB antenna splitter (with code 865 (TV tuner)) →
Tuner unit
In model 166, the DAB 2 signal is received via the following route:
Windshield antenna →
TV 1 antenna amplifier Tuner unit
With DAB reception, the audio equipment sends the FM station lists over the MOST to the tuner unit. If a comparable FM station is found, this is then requested by the tuner unit and the audio equipment provides the FM audio signals on the MOST. If the DAB reception worsens, a switch is made to the audio equipment's FM station, whereby the tuner unit adjusts the time lag between the digital and the analog signal. In this way the switchover is almost inaudible ("Seamless Linking").
The tuner unit transmits the audio signals via MOST to the audio equipment (except CODE 810 (Sound system) and except CODE 811 (Advanced sound system)) or via the audio equipment to the sound system amplifier control unit (with CODE 810 (Sound system) or CODE 811 (Advanced sound system)).
DAB dual tuner
The tuner unit is designed as a diversity tuner and provides the following advantages:
- The background tuner collects the names of all available stations and ensembles for display on the Audio/COMAND display
- Display of data for electronic program index "Electronic Program Guide" on the Audio/COMAND display (e.g. start and finish times of programs, if supported by the station)
- Faster switchover to another Ensemble
- Almost inaudible switchover between various Ensembles with identical program (e.g. Deutschland radio in various Ensembles nationwide)
- Support of the extended audio codecs DAB+ and Digital Multimedia Broadcasting (DMB) audio and therefore reception of programs transmitted with these codecs
Function sequence for Satellite Digital Audio Radio Service (SDARS) (with code 536 (SIRIUS satellite radio))
The tuner unit makes it possible to receive stations from the "Sirius satellite radio" provider. Control of the SDARS system takes place via the audio equipment and is implemented via MOST. The information or displays required for control are output via the Audio/COMAND display and also in the instrument cluster. SDARS also broadcasts real-time traffic data (RTTD) which includes accident and traffic jam messages and traffic flow information. On vehicles with code 531 (COMAND APS) or with code 357 (Map navigation) this data is made available to the navigation module of the audio equipment via MOST. The Sirius satellite radio signal is broadcast 3 times to achieve a diversity of channels (using two satellites and one terrestrial transmitter). The multifunction antenna receives all three channels from the Sirius satellite radio (Sat 1, Sat 2, terrestrial station) and transmits these signals over a direct line to the tuner unit.
Additional function requirements for DVD, CD audio
- No smartphone connected via CarPlay to the multimedia connection unit
Function sequence for DVD, CD audio
The DVD/CD audio function enables audio CDs or audio DVDs (including MP3 and other formats) to be played.
User guidance for controlling DVD and CD functionality and displaying additional information is performed on the Audio/COMAND display. The data exchange between the audio equipment and the Audio/COMAND display takes place via the telematics CAN, but the audio equipment transmits image and video data to the Audio/COMAND display via an LVDS line.
The tuner unit receives and decodes the signals and transmits them via MOST to the audio equipment (except CODE 810 (Sound system) and except CODE 811 (Advanced sound system)) or via the audio equipment to the sound system amplifier control unit (with CODE 810 (Sound system) or CODE 811 (Advanced sound system)).
Additional function requirements for multimedia connection unit
- No smartphone connected via CarPlay to the multimedia connection unit Function sequence, multimedia connection unit
2 USB connectors (universal serial bus) are integrated into the multimedia connection unit and they can be used to connect external devices (e.g. USB memory stick, iPods and MTP devices). The multimedia connection unit sends the signals of the external devices to the audio equipment, on vehicles with code 522 (Audio 20 radio) and code B54 (Live Traffic Information) by way of the USB splitter.
Model 166
as of model year 2016
with code 518 (Media interface)
Model 292
with code 518 (Media interface)
3 adapter cables are enclosed to connect the external devices.
When connecting a device to the multimedia connection unit, the audio equipment switches over to the new media source. The audio equipment emits the audio signals from the connected devices over the speaker system (except CODE 810 (Sound system) and except CODE 811 (Advanced sound system)) or it forwards them over the MOST to the sound system amplifier control unit (with CODE 810 (Sound system) or CODE 811 (Advanced sound system)). User guidance is performed on the Audio/COMAND display. The audio equipment generates the display information and transmits it to the Audio/COMAND display via an LvDS line.
On vehicles with code 522 (Audio 20 radio) and code B54 (Live Traffic Information), external devices can only be used through USB connector 2. The USB connector 1 marked with a battery symbol can only be used for charging an external device on vehicles with code 522 (Audio 20 radio) and code B54 (Live Traffic Information).
As well as the actual media files, metadata that is transmitted to the audio equipment is stored in the connected device. Metadata includes, for example, the title, interpreter, composer, album, genre, audio book, podcast, file identifier, file type (audio or video). This metadata can be displayed and searched by the audio equipment. On vehicles with code 531 (COMAND APS) this meta data is collected by the COMAND controller unit in a memory, the Media Database. It is then possible to search for the relevant metadata in the media database. The Media Database (with CODE 531 (COMAND APS)) permanently stores the metadata of up to three devices. When one of these devices is reconnected, the metadata is updated. As soon as a fourth device is connected, the oldest metadata record is overwritten.
When playing pieces of music, the corresponding cover art is shown on the Audio/COMAND display if the cover art in question is stored in the portable terminal (e.g. iPod). The maximum file size for processing cover art is 5 MB. The audio equipment adapts the resolution to 240 X 240 pixels, 16-bit colors, and converts the file to the JPG format. When searching for albums or pieces of music on the connected device, the matching cover art is also shown on the Audio/COMAND display.
Additional function requirements for SD card (Secure Digital) (with code 522 (Audio 20 radio) or with code 531 (COMAND APS))
- No smartphone connected via CarPlay to the multimedia connection unit
Function sequence for SD card (Secure Digital) (with code 522 (Audio 20 radio) or with code 531 (COMAND APS))
The memory card reader is integrated into the audio equipment. Audio data stored on an SD card can be shown on the Audio/COMAND display by activating the "Memory Card" media source and played back by the audio equipment.
Additional function requirements for storing audio CDs on the COMAND controller unit (with CODE 531 (COMAND APS) and CODE 494 (USA version) or with CODE 498 (Japan version))
- Audio CD is inserted.
- No smartphone connected via CarPlay to the multimedia connection unit.
Function sequence, storing audio CDs on the COMAND controller unit (with CODE 531 (COMAND APS) and CODE 494 (USA version) or with CODE 498 (Japan version))
Audio CDs can be stored on the integrated hard disk of the COMAND controller unit and subsequently retrieved using the "Search" menu. The storage procedure is started during media operation by selecting "REC" in the "Media" menu bar. Only the entire audio CD can be stored on the hard disk. If the storage procedure is canceled prematurely (e.g. by selecting "Cancel"), no data is stored. Stored audio CDs can be retrieved using the "Search" menu in the "Media" menu bar. The individual tracks can also be retrieved using the general search function.
Up to 12 audio CDs can be stored. When 12 audio CDs have been stored, an audio CD must be deleted before a new audio CD can be stored. In order to delete stored audio CDs, a stored audio CD must be played back. A stored audio CD can be selected for deletion using "Options" in the Media menu bar.
Additional function requirements for Bluetooth® Audio
- No smartphone connected via CarPlay or MirrorLink to the multimedia connection unit
Function sequence for Bluetooth® audio
The audio equipment can receive Bluetooth® audio signals from external devices via the Bluetooth® antenna and control the player of the external device. Bluetooth® audio is divided into the following subfunctions:
- Search for devices and authorization
- Connection and reconnection
- Metadata and display of information Search for devices and authorization
The same options exist for the authorization of a Bluetooth® audio source as are available for telephony:
- Search via the device list
- External authorization
The device lists are set up the same for Bluetooth® audio and telephony. In the respective list, only those devices that support the corresponding Bluetooth® profile of the respective function are found or displayed during a search. The Bluetooth® profiles Audio/Video Remote Control Profile (AVRCP) and Advanced Audio Distribution Profile (A2DP) are needed for Bluetooth® audio and the Hands-Free Profile (HFP) is needed for telephony. If a device supports both functions, it appears in both lists after 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/A2DP, all profiles are connected. In this case the device is a telephone and the source of Bluetooth® audio at the same time.
On most devices, it is necessary to start the player on the telephone so that it can then be controlled via the audio equipment.
When starting, the audio equipment proceeds with the following strategy:
- In vehicles with code E07 (Telephone module with Bluetooth® (SAP profile)), the audio equipment first searches for the last two SAP phones (SIM Access Profile) used in the vehicle. The first SAP telephone that replies to the query is connected if it is not connected to any other device via Bluetooth®.
- If no connectable SAP phone is found or in vehicles except code E07 (Telephone module with Bluetooth® (SAP profile)) the last two mobile phones used in the vehicle are searched for. If one of these devices is found, the audio equipment connects to this device. If the device also supports AVRCP/A2DP, these profiles are also connected.
If a device is connected that only supports HFP and a change to the Bluetooth® audio application is made, "No Bluetooth audio device connected" is shown on the audio equipment if corresponding audio sources are shown in the device list.
The "Connect last device" function bar enables the last used Bluetooth® audio source to be connected. However, the connection to the current telephone is interrupted here.
If a device is connected that only supports AVRCP/A2DP and a change to the telephone application is then made, the connection to the device is disconnected and the audio equipment begins the search for the last two telephones.
Metadata and display of information
The display of information for Bluetooth® audio depends on the respective device used. If this device supports AVRCP 1.0 then only "Audio streaming" is shown on the Audio/COMAND display and in the instrument cluster.
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® audio can be found under: http://www.mercedes-benz.com/connect.
| Electrical function schematic for Digital Audio Broadcasting function | Model 292 with code 537 (Digital radio (DAB)) | PE82.60-P-2057-97NBA | |
| Model 166 as of model year 2016 with code 537 (Digital radio (DAB)) | PE82.60-P-2057-97NBB | ||
| Electrical function diagram for audio mode function | Model 292 | PE82.60-P-2058-97NBA | |
| Model 166 as of model year 2016 | PE82.60-P-2058-97NBB | ||
| Electrical function schematic for SDAR function | Model 166 as of model year 2016 with code 536 (SIRIUS satellite radio) Model 292 with code 536 (SIRIUS satellite radio) | PE82.60-P-2060-97NBA | |
| Overview of system components, telematics | GF82.85-P-9999GN |