Navigation, Function - GF82.61-P-2003GN
Model 166
as of model year 2016
with code 357 (Map navigation)
Model 292
with code 357 (Map navigation)
Shown on model 166, 292
Function requirements for map navigation, general
- Circuit 30g ON
- Transport mode not active
- Signals from at least four GPS satellites (Global navigation system)
- Radio switched on
- No smartphone connected via Android Auto or CarPlay
- Authorized SD (Secure Digital) card for code 357 (Map navigation) is inserted in the SD card slot of the radio
The SD card is authorized for the respective radio and can only be used for navigation in this specific radio.
Map navigation, general
The radio is supported by the following vehicle components for the map navigation:
- SD card
- GPS signals from the multifunction antenna, with CODE 348 (Emergency call/assist system) via the global positioning system antenna splitter
- Gyro sensor signals from the gyro sensor integrated in the radio (2D)
- Wheel speed signals via CAN from the Electronic Stability Program control unit
- Reverse gear signal via interior CAN from the electronic ignition lock control unit
- Operation via the left multifunction steering wheel button group and the right multifunction steering wheel button group
- Operation via the Audio/COMAND control panel
- Operation by way of the hands-free system microphone group
- Audio output via the front vehicle speakers, including audio fadeout, with CODE 810 (Sound system) regulated by sound system amplifier control unit
- Image output and map display on the Audio/COMAND display, additionally in the instrument cluster; the view and the menu display are generated by the radio using the SD card data
- Traffic Message Channel (TMC) or similar radio traffic messages via the FM radio tuners (except code 536 (SIRIUS satellite radio) and except code B54 (Live Traffic Information) integrated in the radio and valid subscription for real-time traffic data)
- Real-Time Traffic Data (RTTD) of the Satellite Digital Audio Radio service (SDARS) via MOST from the tuner unit (with code 536 (SIRIUS satellite radio))
- Real-time traffic data via the telematics services communications module and the USB splitter (with code B54 (Live Traffic Information) and valid subscription for real-time traffic data), up to 31.05.2016
- Real-time traffic data via HERMES control unit and the USB splitter (with code 367 (Live Traffic Information) and valid subscription for real-time traffic data), as of 01.06.2016
- Updates of map data and navigation software via SD card to Internet-capable PC
Function sequence for map navigation
The radio 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 radio.
The radio receives the GPS signals from the multifunction antenna for position finding, in vehicles with CODE 348 (Emergency call/assist system) via the global positioning system antenna splitter.
Since GPS operates in the gigahertz range and the signals are weak, the following events may lead to reception interference:
Atmospheric interferences (e.g. bad weather, water vapor, fog), multi-path reception due to reflections of the signals (e.g. at building walls) or signal shadowing (e.g. in built-up areas, in tunnels, due to tall buildings or trees).
In the event of a failure of the GPS signals, the radio reverts back to the basic position finding. For basic position finding, the radio evaluates the data of the integrated gyro sensor as well as the wheel speed signals and the reverse gear signal.
The wheel speed signals are transmitted by the Electronic Stability Program control unit via the following route:
Chassis CAN 1 →
Electronic ignition lock control unit →
Interior CAN →
Radio
The radio receives the reverse gear signal via the interior CAN from the electronic ignition lock control unit.
Position finding errors in position finding, rolling backwards with "circuit 15 OFF" (ignition switched off) or transport of the vehicle falsify the basic position finding. In both cases, this deviation is automatically corrected on receipt of GPS data.
The control signals from the left multifunction steering wheel button group and the right multifunction steering wheel button group are transferred via the following route:
Steering wheel electronics →
Steering LIN →
Steering column tube module control unit →
Chassis CAN 1 →
Electronic ignition lock control unit →
Chassis CAN 2 →
Instrument cluster →
Interior CAN →
Radio
The control signals of the Audio/COMAND control panel are transmitted to the radio via telematics CAN.
The radio receives the voice input through the hands-free system microphone group via a direct line.
The voice output is forwarded by the radio in vehicles except CODE 810 (Sound system) to the speaker system. In vehicles with CODE 810 (Sound system), the radio sends the voice output via MOST to the sound system amplifier control unit. The sound system amplifier control unit amplifies the signals and forwards them to the speaker system.
The radio switches on the Audio/COMAND display via telematics CAN. The picture signals are transferred by the radio via an LVDS line to the Audio/COMAND display. The radio sends the signals for display in the instrument cluster via interior CAN to the instrument cluster.
On vehicles except code 536 (SIRIUS satellite radio), except code B54 (Live Traffic Information), except code 367 (Live Traffic Information) or without a valid subscription for real-time traffic data, the radio takes TMC traffic messages into account. The TMC traffic messages are transmitted within the radio by the integrated FM radio tuners to the navigation processor.
On vehicles with code 536 (SIRIUS satellite radio), the tuner unit receives real-time traffic data (RTTD) via a direct line from the multifunction antenna and provides it to the radio via MOST.
Real-time traffic data (RTTD) include accident and traffic jam messages as well as traffic flow information. The real-time traffic data is available around the major cities in the USA, and is transmitted every 5 minutes.
On vehicles with code B54 (Live Traffic Information), up to 31.05.2016 and with valid subscription for real-time traffic data, the telematics services communication module receives real-time traffic data via the emergency call system antenna from the service provider, as long as the vehicle is located within the geographical area for which the traffic data service is offered. The telematics services communications module forwards the real-time traffic data via the USB splitter to the radio. The telematics services communications module periodically receives position data by way of the USB splitter from the radio. The telematics services communications module sends the position data from the radio over the emergency call system antenna to the service provider. The telematics services communications module therefore contributes to collecting the traffic information from which the map navigation then benefits.
On vehicles with code 367 (Live Traffic Information) as of 01.06.2016 and a valid subscription for real-time traffic data, the HERMES control unit receives the real-time traffic data via the emergency call system antenna or the multifunction antenna (with code 362 (HERMES LTE)) from the service provider, as long as it is within the geographical area for which the traffic data service is offered. The HERMES control unit forwards the real-time traffic data over the USB splitter to the radio. The HERMES control unit transmits the position data from the radio to the service provider via the emergency call system antenna or the multifunction antenna (with code 362 (HERMES LTE)). The HERMES control unit thereby contributes to gathering the traffic information from which the SD card navigation then again benefits.
Updates on the SD card takes are downloaded externally on an Internet-capable PC; this is described in the operator's manual.
| Electrical function schematic for navigation system function | PE82.61-P-2056-97NBA | ||
| Overview of system components, telematics | GF82.85-P-9999GN |