Navigation, function

P82.61-4165-79

Function requirements for map navigation, general

 Circuit 30g ON

 Transport mode not active

 No smartphone is connected via the Android Auto or CarPlay standard.

 Authorized SD (Secure Digital) card for code 357 (Map navigation) inserted into SD card slot of radio

 Signals are available from at least 4 GPS satellites (global navigation system).

 Radio is switched on.

 The SD card is authorized for the respective radio and can then no longer be used for another radio.

Map navigation, general

The radio is supported by the following vehicle components for the map navigation:

 Map data from SD card

 GPS signals from multifunction antenna (with code 362 (HERMES LTE) or with code 386 (Comfort telephony)) or from GPS antenna (except code 362 (HERMES LTE) and except code 386 (Comfort telephony))

 Gyro sensor signals from gyro sensor (2 D) integrated into radio

 Wheel speed signals via CAN from the Electronic Stability Program control unit

 Reverse gear signal via the interior CAN from the front SAM control unit with fuse and relay module

 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 through inside rear-view mirror microphone

 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 map data available

 Traffic Message Channel (TMC) or comparable traffic messages over the FM radio tuner integrated into the radio (except code 536 (SIRIUS satellite radio) and except code 367 (Live Traffic Information) with valid subscription for real-time traffic data)

 Real-time traffic data (RTTD) over MOST from the tuner unit (with code 536 (SIRIUS satellite radio))

 Real-time traffic data over HERMES control unit and the USB splitter (with code 360 (HERMES UMTS), code 367 (Live Traffic Information) and valid subscription for real-time traffic data)

 Updates of map data and navigation software via SD card to Internet-capable PC

 Updates on the SD card takes are downloaded externally on an Internet-capable PC; this is described in the operator's manual.

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 GPS signals are received by the radio over a direct line from the multifunction antenna (with code 362 (HERMES LTE) or with code 386 (Comfort telephony)) or from the GPS antenna (except code 362 (HERMES LTE) and except code 386 (Comfort telephony)).

 As GPS operates in the gigahertz range and the signals are weak, the following events may lead to reception interference: Atmospheric interference (e.g.bad weather, water vapor, fog), multiple reception through signal reflexions (e.g.on building walls) or signal shadowing (e.g.in built-up areas, in tunnels, in the vicinity of tall buildings of 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 Electronic Stability Program control unit sends the wheel speed signals as follows:

Chassis CAN 1 

Front SAM control unit with fuse and relay module 

Interior CAN 

Radio

The reverse gear signal is received by the radio over the interior CAN by the front SAM control unit with fuse and relay module.

 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 instances, the deviation is automatically corrected by the navigation processor integrated into the radio when it receives 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 

Front SAM control unit with fuse and relay module 

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 over the inside rear-view mirror microphone over 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 radio transmits the picture signals to the Audio/COMAND display via an LVDS line (Low Voltage Differential Signal). 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) and except code 367 (Live Traffic Information) with valid subscription for real-time traffic data, the navigation processor in 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 navigation processor of 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 (RTTD) is available around the major cities in the USA, and is transmitted every 5 minutes.

In vehicles with code 367 (Live Traffic Information) and a valid subscription for real-time traffic data, the HERMES control unit receives real-time traffic data from the service provider over the emergency call system antenna or the multifunction antenna (with code 362 (HERMES LTE)) 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 receives cyclical position data from the radio in the opposite direction. The HERMES control unit sends 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 therefore contributes to collecting the traffic information from which the map navigation then benefits.

 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.