Emergency Call System, Function - GF82.95-P-0004RRU
Model 190
up to model year 2017
With Code 348 (Emergency call/assistant system)
Function requirements, emergency call system, general
The emergency call system control unit is not used for regular telephone calls.
- Circuit 30
- Transport mode not active
- Each vehicle-related service is authorized separately.
- The communication module of the emergency call system control unit is configured with the telephone number of the relevant service provider.
- The vehicle owner is registered and authorized at the Service Center.
Emergency call system, general
The emergency call system control unit enables the following vehicle-related services to be realized:
- Authorization ("provisioning")
- Manual or automatic emergency call
- MB information call
- Roadside assistance
- Notification in the event of anti-theft alarm ("Anti Theft Notification")
- Tracking ("stolen vehicle tracking")
- Vehicle remote unlocking
- Vehicle remote locking
- Remote diagnosis ("Remote Diagnosis")
- Transmission of vehicle position ("Vehicle Locator")
- Notification of a certain speed being exceeded ("Speed Alert")
- Notification if a certain area has been reached or left ("Geo Fencing")
- Transmission of information (e.g. map data) to the vehicle ("Remote Information Feed")
- Transmission of updates to vehicle ("Remote Update")
- Visual and acoustic vehicle recognition ("Flash Lights and Sound Horn")
- Internet connection (with CODE 531 (COMAND APS))
The emergency call system function consists initially of the following subfunctions:
- Self-diagnosis
- Display of emergency call system status
- Telephone antenna selection
- Voice connection between vehicle and Service Center
- Position finding
- Data from the supplemental restraint system control unit
- Manual or automatic emergency call
Further subfunctions are described in separate documents:
- Additional telematics services function
- Internet connection function
The Internet connection is not controlled via the emergency call system control unit, but via the head unit. Information on prioritization of services will be provided at the end of this document.
Self-diagnosis
If the emergency call system control unit receives the message "Circuit 15 R" from the electronic ignition lock control unit, the emergency call system control unit performs a self-diagnosis (approx. 8 to 10 s). The light-emitting diodes of the SOS button, the MB-Info button and the breakdown assistance button are on for approx. 10 s.
The "Circuit 15 R" message from the electronic ignition lock control unit is forwarded via the following route:
Interior CAN →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Emergency call system control unit
After a successful self-diagnosis, the emergency call system is operational and the light-emitting diodes go out.
In the event of a fault, a fault message (depending on the fault type) appears on the instrument cluster, and the LEDs on the emergency call system button, the MB-Info button and the breakdown assistance button are permanently illuminated. Depending on the fault type, the fault code is also stored in the emergency call system control unit's fault memory.
Display of emergency call system status
The status of the emergency call system is shown in the following ways:
- Display of status through LEDs
- Display of status in instrument cluster
- Display of status on audio/COMAND display
With some services, no system-specific status indication takes place in the vehicle.
Display of status through LEDs
The LEDs for the SOS button, the MB-Info button and the breakdown assistance button are used to display the following states:
- Self-diagnosis of emergency call system, LEDs light up for approx. 10 s.
- Active service, each LED flashes on and off.
- Fault in emergency call system, LEDs permanently on.
- System readiness of emergency call system, LEDs are off.
- Diagnosis
The emergency call system control unit controls the LEDs in the SOS button, the MB info button and the breakdown assistance button via direct lines.
Display of status in instrument cluster
The status of the emergency call system is indicated in a text message in the instrument cluster in the following instances:
- Active service
- Fault in emergency call system
The emergency call system control unit sends the message 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 →
Instrument cluster
Display of status on audio/COMAND display
An active service of the emergency call system is indicated by a text message or a pop-up window (with confirmation prompt) on the Audio/COMAND display.
The emergency call system control unit forwards the signal for the display of the message or the pop-up window 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
The head unit sends the switch-on signal and control commands to the Audio/COMAND display via telematics CAN.
Additional function requirements for selecting the telephone antenna
- Defect in the left telephone antenna, right telephone antenna or telephone antenna splitter or poor reception
Telephone antenna selection
Normally, the communications module integrated into the emergency call system control unit sends and receives all mobile phone signals via the left telephone antenna or right telephone antenna and the telephone antenna splitter. In the event of poor reception or a defect in the left telephone antenna or right telephone antenna and the telephone antenna splitter, the emergency call system control unit automatically sends and receives the mobile phone signals via the emergency call system antenna.
The emergency call system control unit monitors the left telephone antenna or right telephone antenna and the telephone antenna splitter via a direct line and detects the failure or poor reception. The emergency call system control unit then automatically transmits or receives the mobile phone signals for each vehicle-related service via the emergency call system antenna.
Additional function requirements for voice connection between vehicle and Service Center
One of the following vehicle-related services is present:
- Manual or automatic emergency call
- MB information call
- Roadside assistance
- Vehicle tracking
Voice connection between vehicle and Service Center
Regardless of the type of vehicle-related service initiated (e.g. MB-Info call), a voice connection is established with the Service Center. Following feedback from the Service Center via a special tone, an SMS is sent to the Service Center. This message contains the vehicle position, customer and vehicle identification data and other vehicle data ("Initial Summary"). Then the user can speak to a service receptionist via the existing voice connection.
The driver hands-free system microphone is used for the voice input. The signals from the driver hands-free system microphone are transferred to the head unit, where they are looped through and forwarded to the communications module integrated into the emergency call system control unit. The communications module integrated into the emergency call system control unit then transmits the driver hands-free system microphone signals to the service center. The communications module integrated into the emergency call system control unit transmits and receives the mobile phone signals via the left telephone antenna or right telephone antenna and the telephone antenna splitter.
In the event of a failure of the left telephone antenna or right telephone antenna and telephone antenna splitter or poor reception, the emergency call system control unit automatically transmits and receives the mobile phone signals via the emergency call system antenna.
The establishment of a voice connection to the Service Center is interrupted by the communication module integrated into the emergency call system control unit after several unsuccessful dialing attempts. The cancellation of the connection setup is indicated by a corresponding message in the instrument cluster as well as on the audio/COMAND display. The voice output takes place exclusively via the emergency call speaker (except CODE 810 (Sound system) and except CODE 811 (Advanced Sound System)) or via the center instrument panel midrange speaker (with CODE 810 (Sound system) or with CODE 811 (Advanced Sound System)). The emergency call speaker or the center instrument panel midrange speaker is actuated by the emergency call system control unit via direct lines. The center instrument panel midrange speaker and all other speakers installed depending on the equipment are muted by means of a mute signal from the emergency call system control unit for all other applications (e.g. audio mode).
On vehicles except CODE 810 (Sound system) and except CODE 811 (Advanced Sound System), the mute signal is transmitted to the head unit via a direct line. In vehicles with CODE 810 (Sound system), the mute signal is transmitted via a direct line to the sound system amplifier control unit. On vehicles with CODE 811 (Advanced Sound System), the mute signal is transmitted to the Advanced sound system amplifier control unit via a direct line. Normally, the voice connection is terminated by the Service Center or by the user.
With an emergency call, the voice connection can only be terminated by the Service Center or by ending the telephone connection by pressing the accept/terminate phone call button in the right multifunction steering wheel button group for at least 15 s.
Position finding
The emergency call system control unit 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). Relocating with GPS (after interruption of satellite reception) may require several minutes (up to 20 min. when emergency call system control unit is commissioned). Basic position finding runs parallel to GPS position finding.
The position finding function consists of the following component functions:
- GPS position finding
- Basic position finding
Additional function requirement for GPS position finding
- Circuit 15 R ON or triggering of an authorized service
GPS position finding
The GPS receiver integrated in the emergency call system control unit receives the GPS signals via the global positioning system antenna splitter. The emergency call system control unit calculates the current position of the vehicle (recipient) from the GPS signals. The vehicle's direction of travel is also determined using the sequence of GPS calculated locations.
Additional function requirement for basic position finding
- Circuit 15 R On
Basic position finding
For basic position finding, the emergency call system control unit requires wheel speed and yaw rate signals from the Electronic Stability Program control unit.
The Electronic Stability Program control unit sends the wheel speed and yaw rate signals over the following route:
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Emergency call system control unit
The emergency call system control unit 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 instances, the deviation is automatically corrected by the navigation processor integrated into the emergency call system control unit when it receives GPS data.
Additional function requirement for data from the Supplemental Restraint System control unit
- Circuit 15 R On
Data from the supplemental restraint system control unit
In the event of an accident with airbag deployment, an automatic emergency call (E-Call) is made immediately. An emergency call is sent out regardless of the severity of the accident. The emergency call system control unit receives the
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Emergency call system control unit
The supplemental restraint system control unit sends an operational signal every 500 ms via the path used to send the crash information incl. the crash level. This allows the emergency call system control unit to permanently monitor
crash information via a direct line as a digital crash signal from the Supplemental Restraint System control unit.
The crash information, including crash level, is also (redundantly) forwarded via the following route:
communication with the supplemental restraint unit control unit and proper function of the crash recognition.
Manual or automatic emergency call
In the event that a driver is confronted with an emergency situation while in a remote location, a Service Center employee can obtain an overview of the situation inside the vehicle with the aid of the data received from the emergency call system control unit (voice connection and SMS) and initiate the appropriate action required for help. 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 of rescue workers at the press of a button (own emergency situation, observed accident)
- Reduction in rescue times through fast emergency notification with details on exact location involved
With a manual or an automatic emergency call, the Service Center can transfer the map data to the vehicle if required. The data is made available to the navigation module of the head unit.
With an emergency call, the voice connection can only be terminated by the Service Center or by ending the telephone connection by pressing the accept/terminate phone call button in the right multifunction steering wheel button group for at least 15 s. The signal is forwarded from the accept/terminate phone call button in the right multifunction steering wheel button group via the following route:
Steering wheel electronics →
Steering LIN →
Steering column tube module control unit →
Chassis CAN 1 →
AMG gateway control unit →
User interface CAN →
Instrument cluster
The instrument cluster forwards the signal via the following route:
User interface CAN →
AMG gateway control unit →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Emergency call system control unit
The emergency call function consists of the following subfunctions:
- Triggering of a manual emergency call
- Triggering of an automatic emergency call
- Transmission of the emergency call data and communication with the Service Center
Additional function requirements for triggering a manual emergency call
- A higher-priority vehicle-related service (automatic emergency call) is not active.
Triggering of a manual emergency call
The manual emergency call is triggered by pressing the SOS button in the overhead control panel electronics. The SOS button is covered up with a locking flap. Pressing the protective lid unlocks the lid, and it automatically opens with the aid of a spring mechanism.
The emergency call system control unit reads in the SOS button signals via a direct line.
Triggering of an automatic emergency call
The emergency call system control unit receives a crash signal from the Supplemental Restraint System control unit via a direct line. At the same time, the supplemental restraint system control unit sends the crash signal (redundantly) and the crash level via the following route:
Chassis CAN 1 →
Front SAM control unit with fuse and relay module →
Diagnostic CAN →
Emergency call system control unit
Transmission of the emergency call data and communication with the Service Center
After a manual or automatic emergency call has been initiated, the emergency call system control unit establishes a voice connection to the Service Center. After the Service Center replies with a special tone, the emergency call system control unit automatically transmits an SMS to the Service Center via the integrated communications module.
The SMS automatically sent to the Service Center contains the following data:
- Vehicle position, direction of travel and history
- Vehicle data and crash information
The communications module integrated into the emergency call system control unit transmits and receives the mobile phone signals via the left telephone antenna, right telephone antenna and the telephone antenna splitter.
In the event of a manual or automatic emergency call, other vehicle-related services (e.g. MB-Info call) are interrupted.
In the event of a failure of the left telephone antenna, right telephone antenna and telephone antenna splitter or poor reception, the emergency call system control unit automatically transmits and receives the mobile phone signals via the emergency call system antenna.
If connection to the Service Center cannot be established when an automatic emergency call is initiated, a voice connection is automatically set up using the emergency number whereupon the listed data then has to be communicated verbally.
Prioritization
The emergency call system control unit can manage a voice or data connection and an SMS connection at the same time. The data connection can be used by several services simultaneously by means of transmitting data packets at staggered times. The priority management is based on the following principles:
- Services with SMS capability are executed by SMS if one of the four services with the highest priority is activated and the remaining connection resources are released for the prioritized service.
- Services without SMS capability or an Internet connection are terminated if one of the four services with the highest priority is activated and the connection resources are released for the prioritized service.
- The data recording for remote diagnosis has its own data channel and it can be conducted in addition to any other service.
Services with SMS capability are:
- Tracking ("stolen vehicle tracking")
- Vehicle remote unlocking
- Vehicle remote locking
- Notification of a certain speed being exceeded ("Speed Alert")
- Notification if a certain area has been reached or left ("Geo Fencing")
- Visual and acoustic vehicle recognition ("Flash Lights and Sound Horn")
The four services with the highest priority are listed in the following table.
- The four services with the highest priority are executed if no service with a higher priority is active.
| Priority | Service |
|---|---|
| 1 | Automatic emergency call |
| 2 | Manual emergency call |
| 3 | Roadside assistance |
| 4 | MB Info |
MB-Info and breakdown assistance can be converted into this higher priority service by pressing the button of a higher priority service without the voice connection being interrupted. An MB-Info call is converted to a manual emergency call, for example, if the SOS button is pressed during an active MB-Info call.
| Electrical function diagram for status display of emergency call system function | PE82.95-P-2061-97HBA | ||
| Electrical function diagram for manual or automatic emergency call function | PE82.95-P-2066-97HBA | ||
| Electrical function diagram for voice connection between vehicle and Service Center function | PE82.95-P-2069-97HBA | ||
| Electrical function diagram for position finding function | PE82.95-P-2070-97HBA | ||
| Additional telematics services function | GF82.95-P-2025RRU | ||
| Overview of system components, telematics | GF82.85-P-9999RR |