Audio 20, function - GF82.60-P-0005PNU
MODEL 203.0 /2 /7 as of 1.12.04 with CODE (494) USA version except CODE (528) HIGH Class USA except CODE (530) COMAND APS USA (with navigation system)
The radio (A2) is the central control panel for the entertainment and communications systems integrated in the vehicle within the Media Oriented System Transport (MOST). The radio (A2) is equipped with a monochrome display that can be used to output information such as function button assignment, function status, and operation menus. The following functions can be operated:
- Radio
- Audio amplifier
- CD drive
- Telephone
The radio (A2) can be operated by 2 main control fields, which are located on the left and right next to the display, as well as a rotary switch and a cross-shaped rocker button.
Some functions can be activated using the left multifunction steering wheel button group (S110) and the right multifunction steering wheel button group (S111) of the multifunction steering wheel (MFL).
It should be noted that all button actuations on the MFL are processed first by the instrument cluster (A1). The instrument cluster (A1) links the incoming button actuations with the current menu setting in the multifunction display (A1p13) and transmits a corresponding Controller Area Network bus class B (interior) (CAN-B) message to the radio (A2) if necessary.
MOST bus system
The digital components of the radio (A2) are linked to each other through the Media Oriented System Transport (MOST). The MOST is used to transmit data (control commands and useful information) between the various system components.
Because some of the individual components work with different data formats and require different data transfer rates and security levels, different bus systems have been installed.
The following bus systems are installed:
- Media Oriented System Transport (MOST)
- Controller Area Network bus Class B (interior) (CAN-B)
- Local Interconnect Network (LIN)
The conditions must be met for startup:
- Circuit 15R ON
- Voltage supply (on-board power supply 12 V) applied
- System check (authentication) positive
System activation
If the rotary/push-button switch is pressed, the radio (A2) switches on. In each case the volume can be regulated with the push-button rotary switch for the audio source active. The function keys switch over to the audio source desired by the user. The radio (A2) is operated via:
- Fixed programmed function keys
- Alphanumeric key block
- Eject button
- Programmable function keys
- Rotary/push-button switch with integrated hands-free button
- cross-shaped rocker switch with push-button
- Switch-on button
- Mute button
- Display
- Control buttons on the multifunction steering wheel
- Voice control system (VCS) with code (813) Voice control system (VCS [SBS])
A remote control is not planned.
Interfaces
The data exchange between the radio (A2) and the instrument cluster (A1) takes place via CAN-B. In this manner, the instrument cluster (A1) receives the audio and telephone data as well as the time for the multifunction display (A1p13) in the instrument cluster (A1) via the CAN-B from the radio (A2). The time can also be synchronized between the radio (A2) and the instrument cluster (A1) via the multifunction steering wheel.
The following control units are actuated by the radio (A2):
- CD player with changer (in glove compartment) (A2/6) with code (819) CD changer (6-disc)
- Universal Portable CTEL Interface (UPCI [UHI]) control unit (N123/1) with code (388) "Portable CTEL" for UPCI system
- Voice control system control unit (A35/11) with code (813) Voice control system (VCS [SBS])
- Sound amplifier (A2/13) with code (810) Sound system
- SDAR control unit (N87/5)
Offboard diagnosis, STAR DIAGNOSIS
The radio (A2) has its own diagnostic trouble code memory. When the fault memory is queried with STAR DIAGNOSIS, the data are transmitted over the MOST to the radio (A2) and can then be read out over CAN-B at the interface of the EIS [EZS] control unit (N73).
| Switch on/off behavior, function | GF82.85-P-2006PMD |