LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2019 >> CLS450 Base >> Repair and Diagnosis >> Electrical >> Motors, Switches, Relays >> Electrical System - Body - 257 Chassis 2 Of 8 >> Basic Knowledge >> Telematics Services Function - GF82.85-P-2060FR

Telematics Services Function - GF82.85-P-2060FR

Model 257, 290 

up to model year 2021 

with code 362 (HERMES communications module LTE) 

G14550289Courtesy of MERCEDES-BENZ USA

Shown on model 257 

G14550290Courtesy of MERCEDES-BENZ USA

Shown on model 290 

General telematics services function requirements 

General telematics services 

At the vehicle side, the telematics services are realized by the HERMES control unit via a cellular telephone system connection to the Service Center. The HERMES control unit sends and receives mobile phone signals over the following antennas:

IMPORTANT 2 antennas are used at the same time to achieve transmission and reception diversity.

The telematics services function encompasses the following subfunctions:

IMPORTANT The emergency call, Internet connection and the transfer of real-time traffic data are described elsewhere.

IMPORTANT The vehicle owner can use the Internet site https://www.me.mercedes-benz.com  or the MB-App "Mercedes me" to configure and activate the Mercedes me Portal services.

Overview of the basic telematics services 

The following services, e.g. are available:

Overview of additional telematics services 

The following telematics services are possible, e.g.:

Additional function requirements for voice connection between vehicle and Service Center 

Voice connection between vehicle and Service Center 

IMPORTANT The setup of a voice connection to the Mercedes-Benz Service Center is aborted after several unsuccessful dialing attempts, and a corresponding message appears on the Audio/COMAND display.

The voice connection function between the vehicle and the Service Center is split up into the following subfunctions:

Triggering voice connection through the Mercedes me connect button 

After pressing the Mercedes me connect button, the HERMES control unit establishes a voice connection to the Service Center. The Mercedes me connect button sends the operation signal over the following route:

Overhead control panel control unit →

Interior CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

IMPORTANT At the same time as a voice connection is established, a data telegram is sent to the Mercedes-Benz Service Center containing, e.g. the following data: time stamp, global navigation system (GPS) position, the language configured in the head unit and the vehicle identification number.

As long as the voice connection is activated, the light-emitting diode integrated into the button flashes on and off, to do this, the HERMES control unit actuates the Mercedes me connect button in the opposite direction.

The voice connection is shown on the Audio/COMAND display as follows:

HERMES control unit →

Diagnostic CAN →

Electronic ignition lock control unit →

User interface CAN →

Head unit →

HSVL line →

Audio/COMAND display

The voice connection is displayed by a status message in the telephone menu of the instrument cluster.

The HERMES control unit sends status signals over the following path:

Diagnostic CAN →

Electronic ignition lock control unit →

User interface CAN →

Instrument cluster

IMPORTANT The Service Center can perform a remote diagnosis if necessary.

IMPORTANT If necessary, the Service Center can, e.g. send map data or points of interest to the vehicle. The data is made available to the navigation module of the head unit.

Additional function requirements for triggering the voice connection via the "MB-Contact" address book entry 

Triggering the voice connection via the "MB-Contact" address book entry 

The HERMES control unit sets up a voice connection with the Mercedes-Benz Service Center by selecting the reserved "MB-Contact" telephone book entry.

The permanently reserved address book entry "MB-Contact" can be selected using the following components:

The operation signals from the Audio/COMAND control panel (except code 446 (Touchpad only)) or the touchpad (with code 446 (Touchpad only) or with code 448 (Touchpad)) are forwarded over the telematics CAN to the head unit.

The head unit multifunction steering wheel button group sends the control signals via the following route:

Steering wheel electronics →

Steering wheel CAN →

Steering column tube module control unit →

Suspension FlexRay →

Electronic ignition lock control unit →

User interface CAN →

Head unit

The voice control system is activated on the head unit multifunction steering wheel button group. The voice control system is automatically switched off when the call is set up. When the voice control system is active, the voice commands are recorded by the driver hands-free system microphone and forwarded via a direct line to the head unit.

IMPORTANT The individual voice commands are listed in the "Linguatronic operator's manual".

If the address book entry "MB Contact" was selected, the head unit sends the signal via the following route:

User interface CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

Mute function 

When a voice connection is established, the HERMES control unit sends a signal over a direct line for muting the audio sources (mute function) to the following component, which then actuates the speaker system:

Hands-free 

The hands-free system is not available for telephone calls for the duration of the voice connection.

After a data telegram has been transmitted to the Mercedes-Benz Service Center, the user can speak to a service receptionist via the voice connection. The Mercedes-Benz Service Center carries out the call in the language that was selected in the system settings of the head unit and transmitted in the data telegram, where possible.

The HERMES control unit receives outgoing voice signals from the driver hands-free system microphone via the head unit.

The HERMES control unit outputs the incoming voice signals over the center instrument panel speaker (except code 811 (Advanced Sound System)) or over the center instrument panel midrange speaker (with code 811 (Advanced Sound System)).

The volume of the voice output can be adjusted using the following controls:

The head unit multifunction steering wheel button group sends the volume setting over the following route:

Steering wheel electronics →

Steering wheel CAN →

Steering column tube module control unit →

Suspension FlexRay →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

On model 257 the volume control button of the right lower control panel the volume setting over the following route:

LCP LIN →

Audio/COMAND control panel (except code 446 (Touchpad only)) or Touchpad (with code 446 (Touchpad only)) →

Telematics CAN →

Head unit →

User interface CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

On model 290 the volume control button of the right lower control panel the volume setting over the following route:

Drive Unit CAN →

Drive Unit control unit →

LCP LIN →

Audio/COMAND control panel (except code 446 (Touchpad only)) or Touchpad (with code 446 (Touchpad only)) →

Telematics CAN →

Head unit →

User interface CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

Termination of the voice connection 

The voice connection can be terminated via the head unit multifunction steering wheel button group if is not performed by the Mercedes-Benz Service Center. The head unit multifunction steering wheel button group sends the control signals via the following route:

Steering wheel electronics →

Steering wheel CAN →

Steering column tube module control unit →

Suspension FlexRay →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

Prioritization 

For the services that require a voice connection between the vehicle and the Service Center, the prioritization shown below is valid.

IMPORTANT Telematics services, e.g. accident management, can also be triggered by the Service Center after an emergency call with the user's consent. In this case, the voice connection that was set up for the emergency call is used again by means of transferring within the Service Center. The emergency call is then converted into a service with lower priority.

Priority Service
1 Automatic emergency call
2 Manual emergency call
3 Breakdown Management
4 Concierge service or MB-Info

Position finding 

A determination of the current vehicle position is essential for many telematics services. On vehicles with code 355 (Preinstallation for navigation retrofit) or with code 531 (COMAND APS), the HERMES control unit takes over the signals of the position finding from the head unit. The head unit sends the signals via the following route:

User interface CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

As of 01.06.2019, the HERMES control unit also performs its own position finding. As a result, the HERMES control unit can immediately compensate for a signal failure from the head unit.

Position finding is carried out by the HERMES control unit on vehicles except code 355 (Preinstallation for navigation retrofit) and except code 531 (COMAND APS).

For position finding, the HERMES control unit uses the global navigation system (GPS). GPS is available worldwide. GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). Recalculation of the GPS position (following an interruption in satellite reception) can take several minutes. A basic position finding routine runs in parallel to the GPS position finding routine that makes it possible to also locate the position of the vehicle if GPS reception fails.

The position finding function consists of the following component functions:

GPS position finding (as of 01.06.2019 or for vehicles except code 355 (Pre-installation for navigation retrofit) and except code 531 (COMAND APS)) 

The HERMES control unit receives the GPS signals from the GPS antenna.

Additional function requirements for basic position finding (as of 01.06.2019 or for vehicles except code 355 (Pre-installation for navigation retrofit) and except code 531 (COMAND APS)) 

Basic position finding (as of 01.06.2019 or for vehicles except code 355 (Pre-installation for navigation retrofit) and except code 531 (COMAND APS)) 

The electronic ignition lock control unit sends the status of circuit 15 via diagnostic CAN to the HERMES control unit.

The HERMES control unit requires the following signals for basic position finding:

The Electronic Stability Program control unit sends the wheel speed and yaw rate signals as follows:

Suspension FlexRay →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

The steering wheel angle sensor sends the signal as follows:

Steering column tube module control unit →

Suspension FlexRay →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

The HERMES control unit uses the data to calculate the current vehicle position (longitude and latitude).

IMPORTANT Position finding errors, 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.

Forwarding of data, data requests, display messages and operating requests 

The HERMES control unit forwards the data queries and operating requests received via the cellular telephone system connection to the Service Center via the diagnostic CAN to the electronic ignition lock control unit, from where they are distributed further according to the respective requests. The HERMES control unit receives vehicle data from the electronic ignition lock control unit via the diagnostic CAN and forwards this data and the data of the integrated position finding module via the cellular telephone system connection to the Service Center in accordance with requirements.

On vehicles with code 531 (COMAND APS) or with code 506 (Audio 20 radio NTG 5.5), Internet data are communicated, e.g. for the IP radio service, over the wireless local area network (WLAN) from the radio interface of the HERMES control unit over the WLAN antenna to the head unit.

The content shown on the Audio/COMAND display (e.g. pop-up window, vehicle positioning symbol) is forwarded by the HERMES control unit over the following route:

Diagnostic CAN →

Electronic ignition lock control unit →

User interface CAN →

Head unit →

HSVL line →

Audio/COMAND display

The control communication (e.g. switch on) is sent by the head unit to the Audio/COMAND display via telematics CAN.

Some messages on the audio/COMAND display can be confirmed with the Audio/COMAND control panel (except code 446 (Touchpad only)) or with the touchpad (with code 446 (Touchpad only) or with code 448 (Touchpad)). The Audio/COMAND control panel or the touchpad sends the signals over the following route:

Telematics CAN →

Head unit →

User interface CAN →

Electronic ignition lock control unit →

Diagnostic CAN →

HERMES control unit

The control signals from the Audio/COMAND control panel are forwarded to the head unit via telematics CAN.

For some services, the status of circuit 15 is taken into consideration. The electronic ignition lock control unit sends the signal via the diagnostic CAN to the HERMES control unit.

  Electrical function schematic for telematics services function   PE82.95-P-2074-97XBA
  Overview of system components, telematics   GF82.85-P-9999FR