GF82.60-P-3121RTE Audio 20 Component Description

GF82.60-P-3121RTE Audio 20 Component Description
- with CODE (523) MB Audio 20 radio
- except CODE (494) USA version
- except CODE (498) Japan version

Component Identification:

The radio is installed in the center console.

The radio is a central control and display unit for all the entertainment and communication systems integrated into the vehicle. It can also be controlled using the control buttons in the multifunction steering wheel (MFL) (left multifunction steering wheel button group (S110), right multifunction steering wheel button group (S111)).

The most important task of the radio is to display all the individual components integrated into the system in a uniform and user friendly manner.

The following system components integrated into the unit are controlled by the radio:
^ Radio tuner
^ Basic audio amplifier
^ CD audio drive

The radio consists of 2 control units. These are the control and display group and the audio gateway. Communication of these modules takes place internally via Media Oriented System Transport (MOST).

The following are additionally actuated:
^ Amplifier for sound system (N40/3) (code (810) Sound system
^ CD changer (A2/6) (code (819) 6-disk CD changer)
^ Universal Portable CTEL Interface (N123/1) (UPCI [UHI]) control unit (code (386) Preinstallation for telephone "Handy", UPCI system or code (388) Telephone "Handy", UPCI system)

Other functions
^ MOST ring master
^ Diagnostic interface for the MOST components

Buttons/switches

Component Identification:

Telephone 4-quadrant actuator

Component Identification:

Operation
When switching on the radio via circuit 15 (ignition ON) or by pressing the "ON" hard key, the menu that was displayed last before the unit was switched off is shown (last mode).

Device description
^ DIN control panels with hard and soft keys:
- 12 key block with telephone keys on right side
- 4 soft keys beneath the display
- 8 hard keys on the left side
- Hard keys for CD eject under the display
- Telephone 4-quadrant actuator for telephone connection
- Push/rotary switch for ON/OFF and volume on the left side

^ Display (vacuum fluorescent display (VFD))
^ Controller Area Network bus class B (interior) (CAN-B) and MOST interface (the radio serves as a gateway between the MOST and CAN-B)
^ Operable via the button groups of the multifunction steering wheel
^ Radio with dual tune
^ CD audio drive
^ Basic amplifier output stages
^ MMI for:
- Audio (radio, AUX, CD, CD changer)
- Communication (telephone, SMS) -System settings

Technical specifications
^ Networking with CAN-B
^ Electrical wake-up
^ Displays (radio, CD/CD changer, telephone) in the multifunction display (A1p13) via CAN-B
^ Networking with CD changer, amplifier for sound system and Universal Portable CTEL Interface (UPCI [UHI]) control unit via MOST
^ Cyclical implementation of self-diagnosis (self-calibrating as required)

Audio gateway (AGW)
The audio gateway is integrated in the housing of the radio.

AGW functions
^ Radio dual tuner
^ CAN-B interface
^ MOST ring master (light, power and clock master)
^ Central diagnostic interface for the MOST components

Control of radio functions
^ Receiver for FM and AM (SW, MW, LW)
^ RDS-EON
^ Traffic information radio channel via integral traffic information radio channel decoder (TP/TA)

An external analog audio source can be connected to the radio via the AUX jack in the glove box.

CD drive
^ CD drive for playing audio CDs (in Red Book audio CD standard)
^ Functions
- "Soft eject" and "Soft load"
- "Automatic CD Reload" (if a CD has not been changed after 14 s)
- Track selection via number pad or Track UP/Down
- "Track Scan" (eight second play time),"Random" and "Repeat"
- "Fast Forward" and "Fast Reverse" of the individual tracks

Diagnosis
Diagnosis takes place from the central gateway control unit (N93), via the Control Area Network bus class D (diagnosis) (CAN-D) and to the radio.
The radio forms the interface (gateway) to the connected MOST subscribers.

Configuration via diagnosis
Depending on the national version, the following are programmed at the end of line:
^ the available AM/FM bandwidths
^ start and stop frequencies of the particular frequency band
^ increment for changing frequency in the respective FM/AM band
^ the volume increase for incoming traffic messages (TP)
^ Run-on time after switching off ignition

Other control units in MOST can only be addressed and diagnosed if they are entered into the specified configuration (MOST variant coding).