Emergency Call System, Function - GF82.95-P-0004GWU
Model 463
as of model year 2013 up to model year 2017
with code ZU8 (National version for USA)
Show on model 463
Function requirements, emergency call system, general
- Circuit 30
- Transport mode not active
- An emergency call system control unit communication module authorized for the corresponding vehicle-related service is configured with the telephone number of the corresponding service provider
- The vehicle owner is registered and authorized at the Service Center
- Each vehicle-related service is authorized separately
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")
- 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")
- Sending 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
The emergency call system control unit is not used for regular telephone calls.
The emergency call system function consists initially of the following subfunctions:
- Self-test
- Emergency call system status indication
- 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
Information on prioritization of services will be provided at the end of this document.
Further subfunctions are described in a separate document:
- Additional telematics services function
The Internet connection is not controlled through the emergency call system control unit, but through the COMAND controller unit; and therefore it is not described here, but elsewhere.
Self-test
If the emergency call system control unit receives the "Circuit 15R" message over the diagnostic CAN from the electronic ignition lock control unit, the emergency call system control unit runs a self-test (approx. 5 s).
The LEDs on the emergency call system button, the MB-Info button and the breakdown assistance button go on for approx. 5 s. After a successful self test the emergency call system is then operational and the LEDs go off.
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 is also stored in the emergency call system control unit's fault memory.
Emergency call system status indication
The status of the emergency call system is shown in the following ways:
- Status indication through light-emitting diodes
- Status indication in instrument cluster
- Status indication on the Audio/COMAND display
With some services, no system-specific status indication takes place in the vehicle.
Status indication through light-emitting diodes
The LEDs for the emergency call system button, the MB-Info button and the breakdown assistance button are used to display the following status:
- Emergency call system self-test, LEDs light up for approx. 5 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
The emergency call system control unit actuates the LEDs over the following route:
Diagnostic CAN →
Electronic ignition lock control unit →
Interior CAN →
SAM control unit →
Roof LIN →
Overhead control panel control unit →
Emergency call system button, MB-Info button and breakdown assistance button
Status indication 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 →
Electronic ignition lock control unit →
Interior CAN →
Instrument cluster
Status indication on the 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 sends the text message or the pop-up window via the following route:
Diagnostic CAN →
Electronic ignition lock control unit →
Interior CAN →
COMAND controller unit →
LVDS line →
Audio/COMAND display
Additional function requirements for selecting the telephone antenna
- Defect in multifunction antenna or poor reception
Telephone antenna selection
Normally, the communication module integrated into the emergency call system control unit transmits and receives all mobile phone signals via the multifunction antenna. In the event of poor reception or a defective multifunction antenna, the communication module integrated into the emergency call system control unit automatically transmits and receives the mobile phone signals via the emergency call system antenna.
The emergency call system control unit monitors the multifunction antenna 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 a direct line and 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 to 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 driver can speak to a service receptionist via the existing voice connection.
The hands-free system microphone that is integrated in the inside rear-view mirror (A67) is used for voice input. The signals from the hands-free system microphone are routed via a direct line to the COMAND controller unit. In the COMAND controller unit, the signals from the hands-free system microphone are only looped through and are 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 sends the hands-free system microphone signals to the Service Center. The communication module integrated in the emergency call system control unit transmits and receives the mobile phone signals via the multifunction antenna.
In the event of a failure of the multifunction antenna, (e.g. defective because of a rollover), the communications module integrated into the emergency call system control unit automatically transmits and receives the mobile phone signals via the emergency call system antenna.
The voice output takes place via the center instrument panel speaker. The speaker is actuated over direct lines by the emergency call system control unit.
For all other applications, e.g. the audio mode), the speaker system is muted by a mute signal (mute function) from the emergency call system control unit via a direct line to the sound system amplifier control unit (with code EU9 (Harman Kardon® Logic 7® surround sound system)) or to the COMAND controller unit (except code EU9 (Harman Kardon® Logic 7® surround sound system)). Normally, the voice connection is terminated by the Service Center or by the driver.
The buildup of a voice connection to the Service Center is terminated by the communication module integrated into the emergency call system control unit after several unsuccessful dialing attempts and a corresponding message is shown in the instrument cluster as well as on the Audio/COMAND display.
Position finding
For position finding, the emergency call system control unit uses the satellite supported 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. 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 15R ON or activation of an authorized service
GPS position finding
The GPS receiver integrated into the emergency call system control unit receives the GPS signals over the Global Positioning System antenna splitter from the left front GPS antenna.
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 15R 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 signals via the following route:
Chassis CAN 1 →
Electronic ignition lock control unit →
Diagnostic CAN →
Emergency call system control unit
The current vehicle position (longitude and latitude) is then calculated in the emergency call system control unit.
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 15R ON
Data from the supplemental restraint system control unit
In the event of an accident with airbag actuation, an automatic emergency call (E-Call) is transmitted immediately. An emergency call is sent out regardless of the severity of the accident.
The emergency call system control unit receives the crash information via a direct line as a digital crash signal from the Supplemental Restraint System control unit.
The Supplemental Restraint System control unit also (redundantly) sends the crash information, including crash level, via the following route:
Chassis CAN 1 →
Electronic ignition lock control unit →
Diagnostic CAN →
Emergency call system control unit
The supplemental restraint system control unit transmits a "LIFE" signal ("sign of life" for supplemental restraint system (SRS) control unit) via the same route as the crash information, incl. "crash level", every 500 ms. This allows the emergency call system control unit to permanently monitor 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
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 emergency call system button marked "SOS". The emergency call system 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 signals from the emergency call system button are sent over the following path:
Overhead control panel control unit →
Roof LIN →
SAM control unit →
Interior CAN →
Electronic ignition lock control unit →
Diagnostic CAN →
Emergency call system control unit
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 →
- Electronic ignition lock control unit →
- 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 with the following data to the Service Center via the integrated communication module:
- Vehicle position, direction of travel and history
- Vehicle data and crash information
The communication module integrated in the emergency call system control unit transmits and receives the mobile phone signals via the multifunction antenna.
In the event of a manual or automatic emergency call, other vehicle-related services, (e.g. MB Info call) are interrupted.
If the multifunction antenna malfunctions or the reception quality is poor, the emergency call system control unit automatically sends and receives the mobile phone signals over 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.
With a manual or an automatic emergency call, the Service Center can transfer the map data to the vehicle if required.
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 remote diagnosis has its own data channel, and can also be carried out for every other service.
- The four services with the highest priority are executed if no service with a higher priority is active.
Services with SMS capability are:
- 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.
| Priority | Service |
|---|---|
| 1 | Automatic emergency call |
| 2 | Manual emergency call |
| 3 | Roadside assistance |
| 4 | MB Info |
| Electrical function diagram for status display of emergency call system function | PE82.95-P-2061-97ZGA | ||
| Electrical function diagram for vehicle location, function | PE82.95-P-2064-97ZGA | ||
| Electrical function diagram for manual or automatic emergency call function | PE82.95-P-2066-97ZGA | ||
| Electrical function diagram for voice connection between vehicle and Service Center function | PE82.95-P-2069-97ZGA | ||
| Electrical function diagram for position finding function | PE82.95-P-2070-97ZGA | ||
| Electrical function schematic for MB information and breakdown assistance function | PE82.95-P-2073-97ZGA | ||
| Electrical function schematic for telematics services function | PE82.95-P-2074-97ZGA | ||
| Overview of system components, telematics | GF82.85-P-9999GW | ||
| Additional telematics services function | GF82.95-P-2025GWU |