Audio 50 APS component description - GF82.61-P-4099GZ

MODEL 164 except CODE (494) USA version except CODE (498) Japan version with CODE (525) MB Audio 50 APS radio up to Model Year 2008 

Location 

The radio and navigation unit is installed in the center console.

Task 

The radio and navigation unit 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 panels 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 and navigation unit is to display all the individual components integrated into the system in a uniform and user-friendly manner.

The following system components that are integrated into the unit are controlled by the radio and navigation unit: 

• Arrow navigation with CD-ROM
• Radio tuner
• Basic audio amplifier
• CD audio

The radio and navigation unit consists of 2 control units. These are the control and display group and the audio gateway (AGW). 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) (code (810) Sound system)
• CD changer (A2/6) (code (819) 6-disk CD changer)
• Voice control system (VCS [SBS]) control unit (N41/3) (code (813) Voice control system (VCS [SBS]))
• Universal Portable CTEL Interface control unit (UPCI [UHI]) (N123/1) (code (388) Telephone "Handy", UPCI system)
• An external analog audio source, which can be connected to the radio and navigation unit via the AUX jack in the glove box. Data exchange takes place via a discrete line

Other functions 

• Resource management
• MOST ring master (light, power and clock master)
• Central diagnostic interface for MOST components (via MOST and Controller Area Network bus class B (interior) (CAN-B))
  Fig 2: Identifying Radio And Navigation Unit

  Courtesy of MERCEDES-BENZ USA

Operation 

When switching on the radio and navigation unit 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.

By pressing one of the buttons next to the display, the base functions can be called up:

• Audio
• NAV
• SERV
• CTEL

Device description 

• DIN control panels with hard and soft keys:
  • 12 key block with telephone keys on right side
  • 3 soft keys each on left and right of the display
  • 8 hard keys on the left side
  • 5 hard keys below the display
  • Cross-shaped control switch with confirmation function ("OK") at bottom right
  • A push/rotary switch for "ON/OFF" and volume on the left
• Navigation integrated into the unit (arrow navigation)
• Global Positioning System (GPS) receiver and vibration gyro (for navigation)
• Display (4.9" color display (TFT))
• CAN-B and MOST interface (radio and navigation unit serves as a gateway between MOST and CAN-B)
• Operable via the left multifunction steering wheel button group and the right multifunction steering wheel button group
• Radio with dual tuner
• Basic amplifier output stages
• Processor
• An external analog audio source can be connected to the radio and navigation unit via the AUX jack in the glove box. Data exchange takes place via a discrete line
• MMI for
  • Audio (Radio, CD, CDC, AUX)
  • Navigation
  • Communication (telephone, SMS)
  • Office (address book)
  • System settings

Technical specifications 

• Networking with CAN-B
• Displays (radio, CD/CDC, telephone, navigation) in the multifunction display (A1p13) of the instrument cluster (A1) via CAN-B
• Networking with CD changer (code (819) 6-disk CD changer), amplifier for sound system (code (810) Sound system), VCS [SBS] control unit (code (813) Voice control system (VCS [SBS])) and UPCI [UHI] control unit (code (388) Telephone "Handy", UPCI system) via MOST
• Fast loading of another language for navigation voice outputs (voice output for the navigation feature is possible in multiple languages)
• Determination of the relative changes in direction using turn rate sensor (gyro)
• Determination of the route traveled by the vehicle using wheel pulse counter (RIZ signal) via CAN-B
• Control unit performs a self-test after activation and calibrates itself automatically if needed
• Position finding with GPS
• Dynamic destination-oriented navigation system using radio
• TMC

TMC = Traffic Message Channel. This is a subchannel that permanently and inaudibly transmits traffic information via FM. It is used for text information and for dynamic destination-oriented navigation.

AGW 

The AGW is used as MOST and audio master control unit. It is integrated in the housing of the radio and navigation 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)
• Amplifier output stages (for basic sound)

Control of radio functions 

• Receiver for FM, MW, LW, SW (10 station presets per band)
• Selection of frequency band (manually/automatically)
• Station search (manually/automatically)
• Station preset management (saving and retrieving)
• Traffic information radio channel via integrated decoder (TP/TA)
• Telephone muting (MUTE)
• Decoding and displaying of RDS information (station name, traffic information radio channel)

Software Update 

The radio and navigation unit is updated with an update CD. The AGW software on the other hand is updated via Control Area Network bus class D (diagnosis) (CAN-D).

CD drive 

The standard CD drive is used for playing audio CDs and reading out navigation data CDs.

Self-burned CDs can also be played. The functional capability, however, depends on the blank CDs used and on the burning method; the playback of CD-RWs is limited.

Navigation processor 

The navigation function is run in the radio and navigation unit. For this purpose, a turn rate sensor is also integrated into the unit in addition to the CD-ROM drive. The GPS receiver is located in the roof antenna module (A2/93).

GPS receiver 

It receives signals from GPS satellites (e.g. longitude and latitude, UTC time and date). At least 3 satellites are required for finding the position. The receiver can evaluate and track up to 12 satellites.

Gyro sensor 

The turn rate sensor is a piezo-electric vibration gyro and is used to detect changes in direction (e.g. when cornering).

Diagnosis 

The central gateway control unit (N93) carries out the diagnosis via CAN-D to the radio and navigation unit.

The radio and navigation unit forms the interface (gateway) to the connected MOST subscribers. The "Keyword 2000 protocol" is used.

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