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Navigation Mode, Function - GF82.85-P-2012RDM

Model 172.4 

as of model year 2017 

with code 531 (COMAND APS) 

G13848177Courtesy of MERCEDES-BENZ USA

Shown on model 172.4 

Function requirements for navigation mode in general 

General navigation mode 

The navigation module is integrated in the COMAND controller unit.

The navigation system includes the following functionalities:

The location of the vehicle and the direction and distance to the destination are determined with the aid of the navigation system.

After entering or retrieving a destination location, route calculation starts. A range of options can be selected for route calculation according to the national version, e.g. :

If observance of the options is not possible, then the options set are ignored for the sections in question and a message is displayed and signaled audibly. The set options can be displayed and changed at any time. Once calculated, the route is displayed using arrow pictograms on the Audio/COMAND display and this information is also issued as an acoustic notification: "The route is being calculated".

If the vehicle is no longer moving on the precalculated route, the route is recalculated. If the recalculated values are plausible for the navigation system, then the modified route is displayed.

IMPORTANT Dynamic route guidance (with "Dynamic route", "Dynamic route with confirmation" or "Eco route"): An alternative route is offered under dynamic route guidance, in the event of a sufficiently long traffic jam or road closure on the calculated route.

The navigation system also has lists and card data for points of interest (e.g. restaurants, filling stations, parking lots, shopping centers), which can be selected as the destination or for a stopover.

IMPORTANT Destinations can be sent from the Internet via the "Mercedes-Benz Application Gateway" to the vehicle and imported into the navigation system.

IMPORTANT

Model 172.4 as of model year 2017 with code 531 (COMAND APS) except code 498 (Japanese version)

Routes can be sent from the Internet via the "Mercedes-Benz Application Gateway" to the vehicle and imported into the navigation system.

IMPORTANT

Model 172.4 as of model year 2017

with code 494 (US version)

with code 531 (COMAND APS)

Destination entries or points of interest can be made available to the navigation module of the COMAND controller unit by the Service Center.

The navigation system can be operated with the following components:

When entered using the Audio/COMAND control panel, the control signals are transmitted via the telematics CAN to the COMAND controller unit.

When entries are made through the switch panels on the COMAND controller unit, the control signals are processed within the unit.

The control signals from the left multifunction steering wheel button group and the right multifunction steering wheel button group are forwarded by the steering wheel electronics via the following route:

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 →

COMAND control unit

When operating via the voice control system, voice input takes place using the inside rear-view mirror microphone. Spoken words are converted into an electrical signal via the inside rear-view mirror microphone and forwarded to the COMAND controller unit.

IMPORTANT In the voice control system, additional name lists are provided for navigation e.g. for the following information: place names for selected towns on the data medium, street names for all cities, city centers, and points of interest.

The navigation function consists of the following subfunctions:

IMPORTANT The navigation system uses a special interface to provide data that is used by other systems in the vehicle. The COMAND controller unit sends the data via interior CAN.

General information on GPS position finding 

The GPS is a satellite-based position finding system, which is available on a global basis. GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). Recalculating the GPS position (after satellite reception has been interrupted) can take several minutes (up to 5 minutes during initial commissioning). The accuracy of the position finding and the actual calculation are essentially based on the measurement of the run times of the signals sent synchronously by the various satellites. A vital precondition is the synchronicity of the clocks in the satellites and in the receiver. To ensure synchronicity, the receiver is equipped with an automatic time correction that is possible thanks to the satellite signals.

GPS position finding function sequence 

On vehicles with code 362 (HERMES LTE) or with code 386 (Comfort telephony), the COMAND controller unit receives the GPS signals from the multifunction antenna.

On vehicles except code 362 (HERMES LTE) and except code 386 (Comfort telephony), the COMAND controller unit receives the GPS signals from the GPS antenna.

The COMAND controller unit calculates the current position of the vehicle from the GPS signals. The vehicle's direction of travel is also determined using the sequence of GPS calculated locations.

IMPORTANT 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).

General information on basic position finding 

Navigation can be continued without a GPS signal using basic position finding. A defect (e.g. in the multifunction antenna or the GPS antenna) may therefore not be immediately noticeable. Basic position finding runs parallel to GPS position finding. For basic position finding the COMAND controller unit requires the following information:

Basic position finding function sequence 

For basic position finding, the COMAND controller unit requires signals from the following components:

The gyro sensor and 3-D acceleration sensor data is forwarded within the COMAND controller unit.

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 →

COMAND control unit

The basic position finding calculation is performed approx. once per second.

IMPORTANT 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 COMAND controller unit's integrated navigation processor upon reception of GPS data.

Calibration 

The calibration following a tire replacement is performed automatically.

Recalibration 

Because of the tire abrasion, a constant recalibration of the tire circumference is required. It is carried out automatically and uses the difference between the calculated and actually traveled distance between turning points calculated with the aid of map-based position finding.

General information on route calculation 

Route calculation is accomplished using the options set to the best possible extent. If observance of the options is not possible, then the options set are ignored for the sections in question and a message is displayed and signaled audibly. The set criteria and options can be displayed and changed at any time. Acoustic information is output ("Route is being calculated") and following successful calculation the route is displayed on the map.

Route guidance function sequence 

The integrated navigation processor continuously compares the route calculation data with the position finding data and uses the data to deduce measures for further route guidance. The route guidance is carried out by outputting visual and acoustic information and is divided up into the following areas:

Map route guidance 

Signals for visual depiction of the route guidance (map navigation) are generated by the COMAND controller unit and sent to the audio/COMAND display via an LVDS line. The Audio/COMAND display is switched on via the telematics CAN by the COMAND controller unit.

Route guidance through driving lane recommendations 

For certain turnoff situations on multiple-land exit points (e.g. freeway intersection) driving lane recommendations are shown in the bottom line. In addition, when a turnoff recommendation is given, the distance to the actual turnoff point is also displayed by means of a bar graph.

The lanes have arrows assigned to them, which indicate on which lane the destination can be reached or the best way to reach it.

The following colors are valid for display in the Audio/COMAND display:

IMPORTANT The instrument cluster only displays the white arrows.

Route guidance by means of voice output 

Route guidance by means of voice output is an assistance function that assists the driver without distracting him from the traffic. Voice is output with the selected system language. The route guidance of the navigation system is supported by voice outputs with the following information:

Further voice messages take place, for example, at the start of route calculation, when an intermediate destination has been reached, or when the destination has been reached.

During dynamic route guidance, additional voice messages are issued due to traffic messages affecting the route. Special information is issued in some instances by voice output, for example:

The COMAND controller unit's navigation processor links word segments during a voice output to form complete instructions or information.

IMPORTANT The announcement volume can be adjusted when voice output is active.

In vehicles except CODE 810 (Sound system), voice outputs are forwarded by the COMAND controller unit to the speaker system. On vehicles with CODE 810 (Sound system), the COMAND controller unit 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.

General information on dynamic route guidance 

Dynamic route guidance takes place in "Dynamic route", "Dynamic route with confirmation" or "Eco route" mode (except code 494 (USA version) and except code 498 (Japan version)). During dynamic route guidance the current traffic situation is taken into consideration when appropriate traffic data is received. The traffic data recorder decodes the traffic information and forwards it internally to the navigation processor upon request. The navigation processor makes the decision whether the route should be changed.

During dynamic routing with confirmation, the user is notified of the effects of the route change on the travel distance and driving time. The route is only changed with the user's agreement.

If necessary, a message that the route should be changed is output via the speaker system.

Function sequence for dynamic route guidance (except code 367 (Live Traffic Information) with valid subscription for real-time traffic data and except code 498 (Japan version)) 

The incoming information about the traffic situation can be received by the Radio Data System/Traffic Message Channel (RDS/TMC) function via FM radio or digital radio (DAB) (with code 537 (Digital radio (DAB))) if an appropriate station has been selected.

IMPORTANT

Model 172.4 as of model year 2017

with code 367 (Live Traffic Information)

with code 531 (COMAND APS)

Dynamic route guidance via RDS/TMC is carried out if no real-time traffic data are received over the HERMES control unit (e.g. no valid subscription or the vehicle is not within the geographical area for which the traffic data service is offered).

The FM receiver in the COMAND controller unit receives traffic information, which is then forwarded internally to the traffic data recorder in the COMAND controller unit.

FM signals (FM 1 and FM 2) are received via the following route:

Windshield antenna →

FM, AM and CL antenna amplifier and FM 2, DAB and TV antenna amplifier →

COMAND control unit

On vehicles with code 537 (Digital radio (DAB)), the tuner unit receives two DAB-Band-III signals over the following path:

Windshield antenna →

FM 2, DAB and TV antenna amplifier (DAB 1) and TV 1 antenna amplifier (DAB 2) →

Tuner unit

The tuner unit forwards the traffic messages in the digital radio to the COMAND controller unit. The traffic messages are stored in the traffic data recorder of the COMAND controller unit and made available to the integrated navigation processor.

Function sequence, Vehicle Information and Communication System (VICS) via FM multiplexer (with code 498 (Japan version)) 

The driver is provided with vital information by the VICS on the current traffic situation. Traffic impairments and traffic jams are shown on the map, however they are not incorporated into the dynamic route guidance. The VICS messages are transmitted as FM radio signals.

FM signals (FM 1 and FM 2) are received via the following route:

Windshield antenna →

FM, AM and CL antenna amplifier and FM 2, DAB and TV antenna amplifier →

COMAND control unit

The VICS information is processed in the FM multiplexer integrated into the COMAND controller unit. The information is then sent over the LVDS line to be shown on the Audio/COMAND display.

Function sequence for dynamic route guidance with VICS (with code 498 (Japan version), dealer option) 

The Vehicle Information and Communication System (VICS) control unit and the Dedicated Short-Range Communications control unit are required for dynamic route guidance. The Vehicle Information and Communication System (VICS) control unit contains both the receiver and the antenna. The antenna communicates with the VICS beacons (transmitter masts) installed at the roadside, that send signals within the 2.5 Gigahertz reception range or infrared signals. Received signals are transmitted directly to the COMAND controller unit where they are decoded. The Dedicated Short-Range Communications control unit receives VICS signals in the 5.8 gigahertz reception range via the ETC/DSRC antenna and forwards them to the COMAND controller unit. The traffic messages are stored in the traffic data recorder of the COMAND controller unit. The traffic data recorder decodes the traffic information and forwards this to the navigation processor upon request. The navigation processor makes the decision whether the route should be changed. If necessary, a message saying that the route was changed is issued.

Function sequence for dynamic route guidance with real-time traffic data (RTTD) (with code 536 (SIRIUS satellite radio)) 

RTTD are real-time traffic data that is transmitted through the "Sirius" satellite radio provider and the reception and processing of the data is made possible by the tuner unit. The real time traffic data contain 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. The tuner unit receives the real-time traffic data from the multifunction antenna, and makes the data available to the COMAND controller unit's navigation system over MOST. The COMAND controller unit uses the data to calculate alternative routes and displays them on the Audio/COMAND display over the LVDS line.

Additional function requirements for dynamic route guidance with real-time traffic data over the HERMES control unit (with code 367 (Live Traffic Information)) 

IMPORTANT Once the subscription has ended, or when outside the geographical area for which the traffic information service is made available, only dynamic route guidance is then available with radio traffic messages.

Function sequence for dynamic route guidance with real-time traffic data over the HERMES control unit (with code 367 (Live Traffic Information)) 

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)). The HERMES control unit forwards the real-time traffic data to the COMAND controller unit. The HERMES control unit receives cyclic position data from the COMAND controller unit. Data are exchanged between the HERMES control unit and COMAND controller unit over a USB line (Universal Serial Bus). The HERMES control unit sends the position data from the COMAND controller unit to the service provider via the emergency call system antenna or the multifunction antenna (with code 362 (HERMES LTE)). In this way, the HERMES control unit contributes to collecting the traffic information, from which the dynamic route guidance then benefits in turn.

Map function 

Map display is always controlled by the COMAND controller unit. The following display functions are supported:

Extended navigation functions 

The navigation system is extended with regard to convenience, customization and tourist information by the following functions:

The extended navigation functions are implemented internally in the COMAND controller unit, and - where applicable - shown over the low voltage differential signaling line on the Audio/COMAND display.

  Electrical function diagram for navigation mode (COMAND) function   PE82.85-P-2063-97TAC
  Overview of system components, telematics   GF82.85-P-9999RD 
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