Navigation, Function - GF82.61-P-2003RF
Model 205
up to Model year 2019
with code 357 (Map navigation)
Model 253 (except 253.99)
up to Model year 2020
with code 357 (Map navigation)
Function requirements, general
- Circuit 30g ON
- Transport mode not active
- Authorized Secure Digital (SD) card in the SD card slot on the multimedia connection unit
- Signals from at least 4 global navigation system (GPS) satellites
- Head unit ON
The SD card must be authorized for the head unit.
Map navigation, general
The head unit processes the following input information:
- Map data from the SD card via the multimedia connection unit
- Reverse gear signal and wheel speed signals from the Electronic Stability Program control unit
- GPS signals from the GPS antenna via the global positioning system antenna splitter (with code 348 (Emergency call/assist system))
- Activation of the menu via the upper control panel control unit
- Operation via the Audio/COMAND® control panel or the touchpad (up to 31.05.2015 with code 522 (Audio 20 radio), as of 01.06.2015 with code 448 (Touchpad) or code 494 (USA version) or code 498 (Japan version)), volume control via the relevant lower control + - panel or via the volume control button in the left multifunction til steering wheel button group and the right multifunction steering wheel button group
- Operation via the left multifunction steering wheel button group and the right multifunction steering wheel button group
- Volume adjustment of the audio outputs via the volume adjustment button in the right lower control panel, via the volume control button in the left lower control panel or via the right multifunction steering wheel button group
- Operation of the voice control system via the hands-free system microphone
- Traffic Message Channel (TMC) or comparable radio traffic messages from the FM radio tuners integrated in the head unit (except code 367 (Live Traffic Information) with a valid subscription for real-time traffic data)
- Real-time traffic data from the HERMES control unit (with code 367 (Live Traffic Information) and a valid subscription for real-time traffic data) via the multimedia connection unit (with code B54 (Live Traffic Information) from the SDARS antenna via the tuner unit)
- Updates of map data and navigation software via SD card on Internet-capable PC
The acoustic driving information is output by the head unit via the front speaker system. If necessary, the head unit reduces the volume of any active audio sources.
In vehicles with code 810 (Sound system), the head unit transmits the data via MOST to the sound system amplifier control unit.
The visual driving information is shown on the Audio/COMAND® display. In addition, views and menu displays can be displayed in the instrument cluster. The head unit generates the displays using the SD card data provided by the multimedia connection unit.
Updates on the SD card takes are downloaded externally on an Internet-capable PC; this is described in the operator's manual.
Card navigation
The head unit accesses the map data stored on the SD card.
When the SD card is used for the first time in the vehicle, data is written to a configuration file on the SD card by the head unit.
Since GPS operates in the gigahertz (GHz) range (microwaves) and the signals are weak, the following may lead to reception interference: atmospheric interferences (e.g. bad weather, water vapor, fog), multiple reception due to reflections of the signals (e.g. building walls) or signal shadowing (e.g. in built-up areas, in tunnels, due to higher buildings or trees).
In the event of a failure of the GPS signals, the head unit reverts back to the basic position finding. For basic position finding, the head unit evaluates the data from the integrated gyro sensor as well as the reverse gear signal and the wheel speed signals.
The electronic ignition lock control unit transmits the reverse gear signal to the head unit via the user interface CAN.
The Electronic Stability Program control unit transmits the wheel speed signals to the head unit via the chassis FlexRay, electronic ignition lock control unit and user interface CAN.
Location faults during position finding, rolling backward with circuit 15 OFF or vehicle transportation falsify basic position finding. In both instances, the deviation is automatically corrected by the navigation processor integrated in the head unit upon reception of GPS data. The upper control panel control unit transmits the operation signals via the LCP-LIN, Audio/COMAND® control panel and telematics CAN to the head unit.
The steering wheel electronics reads the control signals from the left multifunction steering wheel button group and right multifunction steering wheel button group directly. The steering column tube module control unit reads these in via the steering LIN and transmits them via the suspension FlexRay, the electronic ignition lock control unit and the user interface CAN to the head unit.
The Audio/COMAND® control panel or the touchpad (up to 31.05.2015 with code 522 (Audio 20 radio), as of 01.06.2015 with code 448 (Touchpad) or code 494 (USA version) or code 498 (Japan version)) transmits the operation signals via the telematics CAN to the head unit. The voice inputs are recorded by the hands-free system microphone and processed further directly by the head unit.
The right lower control panel transmits the operation signals of the volume adjustment button and the left lower control panel transmits the operation signals of the volume control button via the LCP LIN, the Audio/COMAND® control panel and the telematics CAN to the head unit.
The head unit transmits a switch-on request via the telematics CAN and the generated picture data via the LVDS line to the Audio/COMAND® display.
The head unit transmits the information for the display in the instrument cluster to the instrument cluster via the user interface CAN. In vehicles except code 367 (Live Traffic Information) with a valid subscription for real-time traffic data, the navigation processor in the head unit takes TMC traffic messages into account. The TMC traffic messages are transmitted by the integrated FM radio tuners to the navigation processor.
In vehicles with code 536 (SIRIUS satellite radio), the real-time traffic data is received by the SDARS antenna, conditioned by the tuner unit and transmitted via MOST to the head unit.
In vehicles with code 367 (Live Traffic Information) and a valid subscription for the real-time traffic data, the HERMES control unit receives the real-time traffic data via the emergency call system antenna from the service provider, as long as it is within the geographical area for which the traffic data service is offered.
At the end of the subscription or outside of the geographical area for which the traffic data service is offered, the radio traffic messages are evaluated for dynamic route guidance.
The HERMES control unit transmits the real-time traffic data to the head unit via the multimedia connection unit.
The HERMES control unit receives position data from the head unit at regular intervals in the opposite direction. The HERMES control unit transmits the position data from the head unit to the service provider via emergency call system antenna. The HERMES control unit thereby contributes to gathering the traffic information from which the SD card navigation then again benefits.
| Electrical function schematic for navigation system function | PE82.61-P-2056-97FBA | ||
| Overview of system components, telematics | GF82.85-P-9999RF |