Emergency Call System, Function - GF82.95-P-0004RR
Model 190
up to model year 2017
With Code 350 (Ecall emergency call system, Europe)
Except Code 348 (Emergency call/assistant system)
Function requirements, emergency call system, general
- Circuit 30
- Receipt of cyclic readiness signal ("sign of life") from the Supplemental Restraint System control unit
- Connection to emergency call system antenna
- Transport mode not active
- Each vehicle-related service is authorized separately.
- The telematics services communications module is configured with the telephone number of the service provider.
- The vehicle owner is registered and authorized at the Service Center. Emergency call system, general
The emergency call system allows a manual or automatic emergency call to be triggered. The emergency call is received by the Mercedes-Benz Service Center. The user is spoken to in the language that is selected in the system settings of the head unit. If necessary, the Mercedes-Benz Service Center notifies the local rescue services. If the Mercedes-Benz Service Center is not staffed, the emergency call is automatically forwarded to the local rescue services.
If the telematics services communications module receives the message "Circuit 15 R" from the electronic ignition lock control unit over the diagnostic CAN, the module checks the operational readiness of the emergency call system. After a successful check, the emergency call system is operational and "SOS ready" appears on the Audio/COMAND display. The following checks are carried out:
- Connection to GPS antenna
In the event of a fault, depending on the fault type, a fault message appears on the Audio/COMAND display and is stored in the fault memory of the telematics services communications module.
The electronic ignition lock control unit sends the message "Circuit 15 R" via the following route:
Interior CAN →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
The emergency call system function comprises the following subfunctions:
- Emergency call system status indication
- Voice connection between vehicle and Service Center
- Position finding
- Manual or automatic emergency call
Emergency call system status indication
The status of the emergency call system is shown in the following ways:
- Status indication via light-emitting diode
- Status indication on the Audio/COMAND display
The head unit sends information on the status of the voice connection (e.g.
"NO CONNECTION" or "CALL NOT AVAILABLE") to the instrument cluster via user interface CAN. _ _
Status indication via light-emitting diode
The LED of the SOS button is used to indicate the following states:
- Self-diagnosis of emergency call system, LED lights up for approx. 10 s.
- Active service, light-emitting diode flashes.
- Fault in emergency call system, LED on permanently.
- Emergency call system ready for operation, LED is off.
- Diagnosis
The telematics services communications module actuates the light-emitting diode of the SOS button in the overhead control panel electronics via direct lines.
Status indication on the Audio/COMAND display
The status of the emergency call system is indicated by a text message on the Audio/COMAND display in the following cases:
- Emergency call system ready for operation ("SOS ready" in the "Telephone" menu)
- Emergency call has been activated ("activating" (call setup), "transmitting data" (data telegram transmission), "connected" (voice connection established))
- Fault in emergency call system
The telematics services communications module sends the display over the following channel:
Diagnostic CAN →
Front SAM control unit with fuse and relay module →
Chassis CAN 1 →
AMG gateway control unit →
User interface CAN →
Head unit →
LVDS line →
Audio/COMAND display
Control communication between the head unit and Audio/COMAND display takes place via the telematics CAN.
Voice connection between vehicle and Service Center
Once the emergency call has been triggered, the telematics services communications module sets up a voice connection with the Mercedes-Benz Service Center via the emergency call system antenna.
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 telematics services communications module transmits a signal for muting the audio sources to the following components, which actuate the speaker system:
- Sound system amplifier control unit (with code 810 (Sound system))
- Advanced sound system amplifier control unit (with CODE 811 (Advanced Sound System))
- Head unit (except CODE 810 (Sound system) and except CODE 811 (Advanced Sound System))
The hands-free system is not available for telephone calls throughout the duration of the emergency call.
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. The driver hands-free system microphone, which is integrated in the headliner on the driver side, is used for voice input.
The telematics services communications module receives the outgoing voice signals from the driver's hands-free system microphone via the head unit.
The telematics services communications module emits the incoming voice signals at the following speakers:
- Center instrument panel speaker (with code 810 (Sound system) or code 811 (Advanced sound system))
- Emergency call speaker (except CODE 810 (Sound system) and except CODE 811 (Advanced Sound System))
The volume of the voice output can be adjusted using the following controls:
- Right multifunction steering wheel button group
- On/off button with volume control
- Touchpad (with CODE 448 (Touchpad) or with CODE 531 (COMAND APS))
Audio LIN →
Audio/COMAND control panel →
Telematics CAN →
Head unit →
User interface CAN →
AMG gateway control unit →
The signals of the right multifunction steering wheel button group are forwarded via the following route:
Steering wheel electronics →
Steering LIN →
Steering column tube module control unit →
Chassis CAN 1 →
AMG gateway control unit →
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
The telematics services communications module receives the signals from the ON/OFF button with volume control via the following route:
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN
The telematics services communications module receives the signals from the touchpad (with CODE 448 (Touchpad) or with CODE 531 (COMAND APS)) via the following route:
Telematics CAN →
Head unit →
User interface CAN →
AMG gateway control unit →
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN
Position finding
The telematics services communications module uses the satellite-supported global positioning system (GPS) to find its location. 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
- Basic position finding
GPS position finding
On vehicles with code 531 (COMAND APS), the head unit receives the GPS signal from the GPS antenna and forwards it via the following route:
User interface CAN →
AMG gateway control unit →
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
In vehicles with CODE 520 (Audio 20 USB), the telematics services communications module receives the GPS signal from the GPS antenna.
Additional function requirement for basic position finding
- Circuit 15 R On
Basic position finding
The telematics services communications module requires the following signals for basic position finding:
- Wheel speed and yaw rate signals from the Electronic Stability Program control unit
- Steering wheel angle sensor
The Electronic Stability Program control unit sends the wheel speed and yaw rate signals as follows:
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
The signal of the steering wheel angle sensor is forwarded via the following route:
Steering column tube module control unit →
Chassis CAN 1 →
AMG gateway control unit →
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
The telematics services communications module uses the data to calculate the current vehicle position (longitude and latitude).
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.
On vehicles with CODE 531 (COMAND APS), the telematics services communications module receives not only GPS signals from the head unit but also additional position finding data that also supports the basic position finding.
Manual or automatic emergency call
In an emergency situation, a service receptionist in the Mercedes-Benz Service Center can obtain an overview of the situation inside the vehicle with the aid of the data (voice connection and data telegram) received from the emergency call system control unit (N123/4) and initiate appropriate help measures. An emergency call be initiated manually or automatically. These emergency calls are made for the following reasons:
- Automatic alerting of the rescue services after an accident
- Alerting rescue services by pushing a button (own emergency situation, observed accident)
- Reduction in rescue times through fast emergency notification with details on exact location involved
The automatic emergency call has priority over a manually triggered emergency call. If an automatic emergency call is triggered during a manual emergency call, the manual emergency call is interrupted. If a manual emergency call is triggered during an automatic emergency call, it is ignored. However, a data telegram containing updated position data is sent to the Mercedes-Benz Service Center, and the existing connection is maintained.
The manual or automatic emergency call function consists of the following subfunctions:
- Triggering of an automatic emergency call
- Triggering of a manual emergency call
- Transmission of the emergency call data and communication with the Mercedes-Benz Service Center
Additional function requirements for triggering an automatic emergency call
- Circuit 15 R On
Triggering of an automatic emergency call
In the event of an accident with airbag deployment, an automatic emergency call is immediately sent out. An emergency call is sent out regardless of the severity of the accident. The supplemental restraint system control unit sends the crash information, including the crash level as follows:
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Telematics services communication module
The supplemental restraint system control unit transmits a readiness signal cyclically (e.g. every 500 ms) via the same route as crash information. In this way, the telematics services communications module monitors the communication with the Supplemental Restraint System control unit and the correct operation of the crash detection.
An automatic emergency call is also triggered (redundant) if the telematics services communications module receives the "central locking emergency opening" signal and at the same time the cyclic readiness signal ("sign of lift") from the supplemental restraint system control unit is not received. The "Central locking emergency opening" signal is received by the telematics services communications module over the diagnostic CAN from the front SAM control unit with fuse and relay module.
Additional function requirements for triggering a manual emergency call
- No automatic emergency call is active.
Triggering of a manual emergency call
The manual emergency call is triggered by pressing the SOS button.
The telematics services communications module reads in the signals from the SOS button in the overhead control panel electronics via a direct line.
Transmission of the emergency call data and communication with the Mercedes-Benz Service Center
Once a manual or automatic emergency call has been triggered, the telematics services communications module sets up a voice connection with the Mercedes-Benz Service Center. Audio sources are muted, and existing telephone connections are interrupted. The status of the connection setup is indicated by the following messages on the Audio/COMAND display:
- "Activating" (setting up the call)
- "Transmitting data" (transmission of emergency call data (data telegram))
- "Connected" (voice connection established)
The telematics services communications module transmits the messages via the following route:
Diagnostic CAN →
Front SAM control unit with fuse and relay module →
Chassis CAN 1 →
AMG gateway control unit →
User interface CAN →
Head unit →
LVDS line →
Audio/COMAND display
As soon as a connection to the Mercedes-Benz Service Center is established, the telematics services communications module automatically transmits two SMS messages via the emergency call system antenna using Message Access Profile (MAP) to the Service Center. The text messages contain the following information:
- Time stamp
- Global Positioning System (GPS) position of vehicle
- Language
- Vehicle identification number
- MB Contact status (ON or OFF)
Once the text messages have been transmitted, the voice connection is set up. The telematics services communications module first transmits a shortened data telegram using the dual tone multiple frequency (DTMF) via the voice connection. Then the user is contacted by a service receptionist from the Mercedes-Benz Service Center.
To avoid any unintentional termination, the Accept/Terminate phone call button on the multifunction steering wheel is temporarily disabled while the connection is being established during an automatic emergency call. Pressing the accept/terminate phone call button 2 times briefly in succession can interrupt the automatic emergency call.
| Electrical function diagram for manual or automatic emergency call function | PE82.95-P-2066-97HBB | ||
| Overview of system components, telematics | GF82.85-P-9999RR |