Audio 20 component description - GF82.60-P-3121GZ

MODEL 164.1/8 except CODE (494) USA version except CODE (498) Japan version with CODE (523) MB Audio 20 radio up to Model Year 2008 

Location 

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 via 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 in the device are controlled by the radio: 

• Radio tuner
• Basic audio amplifier
• CD audio

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).

Moreover, the following external components are actuated:

• Amplifier for sound system (N40/3) with code (810) Sound system
• CD changer (A2/6) with code (819) 6-disk CD changer
• Universal Portable CTEL Interface (UPCI [UHI]) control unit (N123/1) with code (388) Telephone "Handy", UPCI system
• An external analog audio source, which can be connected to the radio via the AUX jack in the glove box. Data exchange takes place via a discrete line

The radio does not support Bluetooth.

Other functions: 

• MOST ring master (light, power and clock master)
• Central diagnostic interface for the MOST components

Buttons/switches 

Telephone 4-quadrant actuator 

Operation 

When switching on the radio via circuit 15 (ignition ON) or by pressing the push/rotary switch for ON/OFF and volume, 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 key 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
• Control Area Network bus class B (interior) (CAN-B) and MOST interface (the radio serves as a gateway between MOST and CAN-B)
• Operable with left multifunction steering wheel button group and right multifunction steering wheel button group
• Radio with dual tuner
• CD audio drive
• Basic amplifier output stages
• AUX jack (in glove box for an external analog audio source)
• MMI for:
  • Audio (radio, CD, CD changer, AUX)
  • 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 (A2/6), amplifier for sound system (N40/3) and Universal Portable CTEL Interface (UPCI [UHI]) control unit (N123/1) via MOST
• Cyclical implementation of self-diagnosis (self-calibrating as required)

Audio gateway (AGW) 

The audio gateway is fully integrated in the housing of the radio as an audio master control unit.

AGW functions 

• Radio dual tuner (is the radio component in the system)
• CAN-B interface
• MOST ring master (light, power and clock master)
• Central diagnostic interface for the MOST components (via MOST and CAN-B) (for basic sound)
• Amplifier output stages, on vehicles except code (810) Sound system

Control of radio functions 

• Receiver for frequency modulation (FM) and amplitude modulation (AM)
• Radio Data System - Enhanced Other Networks (RDS-EON)
• Traffic information radio channel via integrated traffic information radio channel decoder

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" (8 s 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:

• available AM/FM band widths
• 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)
• shut-off time after switching off the ignition

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