LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Smart >> 2017 >> Fortwo Proxy, 2D Convertible, Standard Trans >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Wiper/Washer Systems >> Electrical System - Body - 453 Chassis - 1 Of 2 >> Basic Knowledge >> Audio Mode, Function >> Audio Mode, Function - GF82.85-P-2030KJ
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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

MODEL 453.0/3/4 

with CODE 537 (smart Audio system) 

except CODE 535 (smart Media system) 

G12096481Courtesy of MERCEDES-BENZ USA

Function requirements, audio mode, general 

General information on the audio mode 

The audio mode consists of the following component functions:

Audio mode functions are selected using the following controls:

In vehicles without code 810 (Sound system), the radio outputs the audio signals over the vehicle's speaker system. In vehicles with code 810 (Sound system), the radio forwards the audio signals to the sound system amplifier control unit, which actuates the speaker system.

IMPORTANT More detailed information on the speaker system is available in the "Speaker output function" document. The radio has diagnosis capability, and the fault memory can be interrogated via the diagnostic connector using XENTRY Diagnostics.

Function sequence for volume and sound settings 

All volume and tone settings are performed using the radio. This is performed either by the user or automatically by the radio. The volume and tone settings are shown on the radio display. The tone settings can be adjusted by pressing the "SETUP" button and then navigating to "Settings", "Audio" and "Tone". The manufacturer default settings can be restored in the system settings. In vehicles with code 810 (Sound system), as well as the general sound settings (balance, bass/treble) the radio is also equipped with the additional "Arkamys" bass boost effect sound setting.

The volume and tone setting partial function is subdivided into the following subfunctions:

Function sequence for manual volume and sound settings 

The manual volume and tone settings function is subdivided into the following subfunctions:

IMPORTANT The desired settings are forwarded on vehicles with code 810 (Sound system) to the sound system amplifier control unit, where they are then processed. In vehicles without CODE 810 (Sound system), the selected settings are processed internally. Audio output via the speaker system is interrupted by pressing the mute function button or using the corresponding button on the radio.

Function sequence for speaker settings using the right multifunction steering wheel button group (vehicles with code K36 (Instrument cluster with 8 9 cm (3, 5") color display)) 

Specific functions and the volume adjustment are set by pressing the volume (+) button and volume (-) button, which increases or decreases the volume for the audio sources.

The control signals are forwarded to the radio via the following route:

Function sequence for volume and tone settings via the radio 

Operating the control on the radio increases or reduces the volume.

Function sequence for speed-dependent volume adjustment 

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 audio gateway control unit transmits vehicle speed information to the radio via telematics CAN. The audio gateway control unit receives this information about the vehicle speed from the Electronic Stability Program control unit, which reads in the signals of the rear axle rpm sensors to calculate the vehicle speed and transmits it to the instrument cluster and the audio gateway control unit via the interior CAN. The Smart Radio Multimedia Navigator receives the vehicle speed signal via the telematics CAN and adapts the volume to the speed displayed in the instrument cluster.

In vehicles with code 810 (Sound system), the audio gateway control unit forwards vehicle speed information to the sound system amplifier control unit via the telematics CAN.

The radio increases or decreases the output level depending on this information.

Function sequence for radio mode function (FM/AM) 

The antennas receive signals for the FM (ultra-short wave), AM (medium wave) and short wave (SW) frequency bands (not available in all national versions). The following useful signals relevant for the radio reception are modulated onto these signals:

The radio receives the FM-1, FM-2 and AM signals via direct lines from the FM, AM and DAB antenna

The radio operation is activated via the "RADIO" button in the left button group on the radio. The radio mode function sequence consists of the following subfunctions:

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). The AM tuner integrated into the radio demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).

FM single tuner with multi-path reception (FM) 

For the FM radio frequency band, the useful signals are broadcast using frequency modulation (FM). The single FM tuner integrated into the radio demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).

Function sequence for radio data system (RDS) 

IMPORTANT Traffic announcements (TA)

In addition to the radio program, many radio stations (FM) also broadcast additional digital information such as station name and traffic message channel recognition. This additional information is evaluated and displayed by the radio and shown on the integrated display if the following requirements are met:

Function sequence for digital radio (DAB) (with code C04 (Digital radio (DAB))) 

The tuner unit integrated into the radio permits the reception of digital radio in DAB format. With DAB, the stations are categorized into groups, so-called "Ensembles", in the "DR Event" submenu. Control of the DAB functions is accomplished via the radio. The information or displays required for control are shown on the radio display. The tuner unit receives the DAB signals as DAB band III signals.

The tuner unit receives the DAB signals via the FM, AM and DAB antenna

Reception-specific switchover from DAB to FM 

The radio transmits the FM station lists to the tuner unit. If a comparable FM station is found, it is requested by the tuner unit. If the DAB reception starts to deteriorate, the radio switches to the FM station.

Function sequence for additional connections at the radio 

The Universal Serial Bus (USB) and auxiliary (AUX) audio sources can be called up via the "MEDIA" button in the left-hand button group of the radio. An appropriate distinction must therefore be made between the following function sequences during media operation:

Additional function requirements for USB 

Function sequence for USB 

After selecting the USB media source, audio files from the connected USB mass storage device can be played over the radio. The USB connector is integrated on the user interface of the radio.

AUX function sequence 

After selecting the AUX media source, audio files from the connected AUX mass storage device can be played over the radio. The AUX connector (A2x1) is integrated on the radio.

Function sequence for Bluetooth® audio/telephone 

The radio can receive Bluetooth® audio signals from external devices via the Bluetooth® antenna. Bluetooth® audio is divided into the following subfunctions:

Search for devices and authorization 

The following options are available to authorize a Bluetooth® audio source:

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 Audio/Video Remote Control Profile (AVRCP) and Advanced Audio Distribution Profile (A2DP) Bluetooth® profiles 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 HFP, AVRCP and A2DP, all profiles are connected. In this case the device is a telephone and the source of Bluetooth® audio at the same time.

With the majority of devices, the player has to be started on the telephone so that it can then be controlled via the radio.

The radio uses the following strategy when starting: First it is checked whether an authorized telephone has been placed in the mobile phone cradle. If this is the case, the radio connects to the telephone and is in comfort telephony status. If no mobile phone cradle is present or no telephone has been inserted, the radio searches for the last two telephones.

If one of the last two telephones is found, the radio connects itself to this device. If this device also supports AVRCP or A2DP, these profiles are also connected.

If a device is connected that only supports HFP and the system is switched to the Bluetooth® audio application, "No Bluetooth® audio device connected" appears on the display of the radio, provided that appropriate 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 or A2DP and the system is switched to the telephone application, the connection to the device is disconnected and the radio starts to 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 radio display.

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.

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

Connection and control of a smartphone with the smart audio system via "smart cross connect" (vehicles with code C67 (Smartphone bracket)) 

Additional function requirements:

In combination with the smartphone bracket, which can be fixed centrally on the radio and adjusted with regard to size, a smartphone can be connected to the smart audio system and controlled via Bluetooth®.

The "smart cross connect app" enables the following functions to be used for the audio mode:

IMPORTANT Additional information on the "smart cross connect app" is available on the official smart website. The "smart cross connect app" can be downloaded from the "smart App Center". Additional information on connecting the mobile phone to the radio and on operation is available in the operator's manual.

  Electrical function diagram for audio mode function   PE82.60-P-2058-97BBA
  Overview of system components, telematics   GF82.85-P-9999KJ 
scientia non olet · About LEMON Manuals