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Home >> Mercedes Benz >> 2009 >> C 300 (204.054) V6-3.0L (272.947) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> GF82.60-P-2003CE Volume/Tone Adjustments, Function

GF82.60-P-2003CE Volume/Tone Adjustments, Function



GF82.60-P-2003CE Volume/Tone Adjustments, Function
- with CODE (523) MB Audio 20 radio
- with CODE (510) Audio 20 with CD changer


Function requirements, general
^ C. 30g ON or c. 15R ON
^ Audio system authorized and operating properly
^ Audio source in operation

Volume/tone adjustments, general
All volume and tone settings are performed using the radio (A2). This is conducted either by the user or automatically by the radio, e.g. by means of the speed-dependent volume control (SDV [GAL]). The volume and sound settings are shown on the audio/ COMAND display (A40/8). Predefined settings can be selected and reset to the manufacturer default setting via the system settings.

On vehicles with code (810) Sound system, the audio unit is provided with a sound setting "Logic 7" (room sound) in addition to the general sound settings (tremble, basses, balance and fader).

On vehicles without code (810) Sound system, the audio signals are relayed to the following speakers via direct line and output from there:
- Left front door speaker (H4/1)
- Right front door speaker (H4/2)
- Left rear door speaker (H4/3)
- Right rear door speaker (H4/4)

On vehicles with code (810) Sound system, the radio transmits the audio signals to the sound system amplifier control unit (N40/3) via the media-oriented system transport (MOST). The sound system amplifier control unit processes them and relays them to the following speaker via a direct line:
- 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 signals for the rear bass speaker (H4/38) are transmitted from the sound system amplifier control unit to the rear bass speaker amplifier (N40/9) and from there to the rear bass speaker via direct lines.

The volume setting can be carried out separately for each audio source. Predefined settings can be selected or reset to the manufacturer default setting using the system settings (button "SYS" on radio).

The volume and sound settings are subdivided into the following partial functions:
^ 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/sound settings are subdivided into the following subfunctions:
^ Function sequence for volume settings via right multifunction steering wheel button group (S111)
^ Function sequence for radio volume settings
^ Function sequence for sound settings via audio/COMAND control panel (A40/9)

Function sequence for volume settings via right multifunction steering wheel button group
Pressing the + and - button for adjustment of specific functions and volume control (S111s1) enables the volume for the desired audio function to be increased or reduced.

The control signals are forwarded via the following path to the radio:
- Steering LIN (LIN E1)
- Steering column module control unit (N80)
- Chassis CAN (CAN E)
- Instrument cluster (A1)
- Interior CAN (CAN B)

After evaluating the control signals, the requested adjustment on vehicles with code (810) Sound system, are relayed with MOST to the sound system amplifier control unit and amplified by the latter. On vehicles without code (810) Sound system, the selected settings are processed and amplified internally.

The audio output via the speaker system is interrupted by actuating the mute button (S111s6).

Function sequence for volume settings on radio
Operating the radio's rotary actuator enables the volume to be raised or lowered for the desired audio function. By actuating the "Sound" button on the COMAND control unit, the menu "Sound" is called and the user can set the corresponding sound via the audio/ COMAND control panel.
The control signals are processed inside the radio. On vehicles with code (810) Sound system, the selected settings are relaye via MOST to the sound system amplifier control unit where they are amplified.
On vehicles without code (810) Sound system, the selected settings are processed and amplified internally.

The audio output via the speaker system is interrupted by actuating the "MUTE" button.

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 control signals of the Audio/COMAND control panel are forwarded to the radio via the telematics CAN (CAN A). On vehicles with code (810) Sound system, the selected settings are relayed via MOST to the sound system amplifier control unit where they are amplified.
On vehicles without code (810) Sound system, the selected settings are processed and amplified internally.

Function sequence for speed-dependent volume control
The volume is adapted to the noise level in the vehicle interior with the aid of the speed-dependent volume control defined by the vehicle speed. For this purpose the instrument cluster transmits information on the vehicle speed to the radio via the interior CAN.

According to this information, the radio increases the output level or lower it.
On vehicles with code (810) Sound system, the radio transmits the corresponding audio signals via MOST to the sound system amplifier control unit, which correspondingly actuates the speaker system.





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