Operation CHARM: Car repair manuals for everyone.
Home >> Mercedes Benz >> 2005 >> SLK 350 (171.456) V6-3.5L (272.963) >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> GF82.85-P-2030RCA Audio Mode, Function

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



GF82.85-P-2030RCA Audio Mode, Function
- with CODE (510) Audio 20 with CD changer


Function requirements
^ Status "Circuit 30 ON" or "Circuit 15R ON"
^ The radio is authorized and in perfect working order
^ No fault in antenna system (radio function)
^ Audio-CD is inserted (for disk operation)
^ A Radio Data System (RBDS) station is set and the RDS function active (for vehicles except code (494) USA version)
^ A Radio Broadcast Data System (RBDS) station is set and the RBDS function active (for vehicles with code (494) USA version)
^ The radio station also transmits additional digital information
^ Traffic Announcement (TA) function set on the radio

General audio mode function sequence
The audio mode function consists of the following function sequences:
^ Radio mode function sequence (AM/FM)
^ Disk function sequence

Further subfunctions are described in separate documents:
^ Digital Audio Broadcasting (DAB), with code (537) Digital radio and with code (833) Great Britain version
^ Satellite digital audio radio (satellite radio) (SDAR), with code (536) SIRIUS satellite radio
^ Media interface, with code (518) Media interface

Operating instructions
Audio functions are operated using the following components:
- Left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)
- Control buttons on radio (A2)

Radio mode function sequence (AM/FM)
The function sequence is subdivided into the following subfunctions:
^ Radio mode function sequence (AM/FM), except code (494) USA version
^ Radio mode function sequence (AM/FM), with code (494) USA version
^ AM tuner function sequence (MW/LW/SW)
^ FM tuner function sequence with phase diversity (PFM/ Weather band (WB)/Traffic Message Channel (TMC))
^ Radio Broadcast Data System (RBDS) or Radio Data System (RDS) function sequence

Radio mode function sequence (AM/FM), except code (494) USA version
The rod antenna (A28) receives high frequency (HF) signals for the FM and AM radio frequency bands. The following useful signals relevant for the radio reception are modulated onto these HF signals:
- Music signals
- Speech signals
- Data signals (e.g. TMC messages (traffic information))

The HF signals are routed to the left antenna amplifier module (A2/64) via direct lines. The left antenna amplifier module filters the radio frequency band frequencies from the HF signals received, and amplifies these.

The amplified signals are then sent via coaxial cable (FM, AM) to the tuner integrated in the radio, where they are demodulated. The demodulated audio signals in vehicles with code (810) Sound system are transferred by the radio via the Media Oriented System Transport (MOST) to the sound system amplifier (N40/3), where they undergo final amplification.
The audio is then output by the following speakers via direct lines:
- Left door speaker group (H4/1)
- Right door speaker group (H4/2)
- Left rear speaker (H4/7)
- Right rear speaker (H4/8)
- Center cockpit speaker (centerfill) (H4/27)
- Left door tweeter (H4/33)
- Right door tweeter (H4/34)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/57)

In vehicles except code (810) Sound system, the audio signals undergo final amplification by the radio and are then output on the following speakers via direct lines:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter

Radio mode function sequence (AM/FM), with code (494) USA version
The rod antenna (A28) receives high frequency (HF) signals for the FM and AM radio frequency bands. The following useful signals relevant for the radio reception are modulated onto these HF signals:
- Music signals
- Speech signals
- Data signals (e.g. weather information via WB)

The HF signals are routed to the left antenna amplifier module (A2/64) via direct lines. The left antenna amplifier module filters the radio frequency band frequencies from the HF signals received, and amplifies these. The amplified signals are then sent via coaxial cable (FM, AM) to the tuner integrated in the radio, where they are demodulated.

In vehicles with code (810) Sound system, the radio routes the demodulated audio signals via the MOST to the sound system amplifier, where they undergo final amplification. The audio signals are then output on the following speakers over discrete lines:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter
- Left rear surround speaker
- Right rear surround speaker

In vehicles except code (810) Sound system, the audio signals undergo final amplification in the radio and are then output on the following speakers via a direct line:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter

AM tuner function sequence (MW/LW/SW)
For the MW, LW and SW 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 tuner function sequence with phase diversity (FM/WB/ TMC)
For the FM radio frequency band, the useful signals are broadcast using frequency modulation (FM). The FM tuner integrated into the radio demodulates these signals. In other words, it also separates the useful signals (audible frequencies) from the carrier signal (inaudible).

Function requirements for RBDS, with code (494) USA version, or RDS, except code (494) USA version
^ RBDS or RDS station set.
^ "RBDS" or "RDS" function activated.

RBDS function sequence, with code (494) USA version, or RDS, except code (494) USA version
As well as the normal radio program, many radio stations (FM) transmit additional digital information such as the station name, the program type (PTY) (e.g. pop, culture, etc.) and traffic program identification.

The additional digital information is evaluated and displayed by the radio.

Disk function sequence
The disc function sequence comprises the following subfunction sequences:
^ CD function sequence or MP3
^ AUX function sequence, except code (518) Media interface

CD function sequence or MP3
A 6-disk CD changer is integrated into the radio. The CD changer is used to read in the audio CDs (including in MP3 format) and they are internally processed by the radio. The user guidance for control of the CD functions (e.g. track selection) and for showing supplemental information (e.g. title) is accomplished on the radio display.

The occupied CD slots are indicated on the radio display. CD slots "1" to "6" are numbered consecutively. The CD menu and title menu, which are also shown on the radio display, are stored on the inserted CD. This is why the functional scope and menu display are dependent on the actual CD inserted.

In vehicles with code (810) Sound system, the radio routes the audio signals via the MOST to the sound system amplifier, where they undergo final amplification.

The audio output is then sent from the sound system amplifier to the following speakers via direct lines:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter
- Left rear surround speaker
- Right rear surround speaker

In vehicles except code (810) Sound system, the audio output is sent via direct lines by the radio to the following speakers:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter

AUX function sequence, except code (518) Media interface
If an external device (e.g. MP3 player) is connected in the glove compartment, the basic display appears. The following appears on the display of the radio:
- Status line
- No display

- Field of application
- No display, 2 speaker symbols only

- Function line
- "AUX" and "Tone"

The associated submenus can be called up on the radio display in the following menu items:
- "AUX" menu item
- No other submenus

- "Tone" menu item
- Treble
- Bass
- Balance/Fader
- Surround sound, with code (810) Sound system

The menu navigation and display of the connection options are shown on the display of the radio and are dependent on the respective portable terminal connected.

In vehicles with code (810) Sound system, the radio routes the audio signals via the MOST to the sound system amplifier, where they undergo final amplification.
The audio output is then sent from the sound system amplifier to the following speakers via direct lines:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter
- Left rear surround speaker
- Right rear surround speaker

In vehicles except code (810) Sound system, the audio output is sent via direct lines by the radio to the following speakers:
- Left door speaker group
- Right door speaker group
- Left rear speaker
- Right rear speaker
- Center cockpit speaker (centerfill)
- Left door tweeter
- Right door tweeter





pro multis · About Operation CHARM