(Emergency Call System, Function - GF82.95-P-0004GRV)

MODEL 166 up to model year 2016 with CODE 348 (Emergency call/assistant system) 

Courtesy of MERCEDES-BENZ USA

Function requirements 

• Terminal 30
• Each vehicle-related service is authorized separately

Selftest 

If the emergency call system control unit receives the "Circuit 15R" message from the electronic ignition lock control unit, the emergency

• 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
• Transport mode not active

call system control unit performs a self-test (approx. t = 3.5 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.

The emergency call system control unit receives the "Circuit 15R" message via the diagnostic CAN from the electronic ignition lock control unit.

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.

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 detection

("Flash lights and sound horn")

• Internet connection (with CODE 512 (COMAND APS with DVD changer))

The emergency call system control unit is not used for regular telephone calls.

The emergency call system function consists initially of the following subfunctions:

• 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

Information on prioritization of services will be provided at the end of this document.

The other subfunctions are described in separate documents:

• Additional telematics services function
• Internet connection function

The Internet connection (with CODE 512 (COMAND APS with DVD changer)) is not controlled via the emergency call system control unit, but by the COMAND controller unit.

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 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 in the emergency call system button, the MB info button and the breakdown assistance button via the following route:

• Diagnostic CAN
• Electronic ignition switch control unit
• Interior CAN
• SAM control unit
• Roof LIN
• Overhead control panel control unit
• Direct line

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 transmits the message to the instrument cluster via the following route:

• Diagnostic CAN
• Electronic ignition switch control unit
• Interior CAN

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 (with confirmation prompt) on the Audio/COMAND display.

The emergency call system control unit transmits the text message or the pop-up to the Audio/COMAND display via the following route:

• Diagnostic CAN
• Electronic ignition switch control unit
• Interior CAN
• COMAND control unit
• LVDS line

Actuation of light-emitting diodes for emergency call system status 

Courtesy of MERCEDES-BENZ USA

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, a Short Message Service (SMS) message is transmitted 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 group integrated into the inside rearview mirror (A67), is used for voice input. The signals from the hands-free system microphone group are routed via a direct line to the COMAND controller unit. In the COMAND controller unit, the signals from the hands-free system microphone group are only looped through and are forwarded to the communication module integrated into the emergency call system control unit.

The communication module integrated into the emergency call system control unit then transmits the hands-free system microphone group signals to the Service Center. The communication module integrated into the emergency call system control unit transmits and receives the mobile phone signals via the following route:

• Direct line
• Multifunction antenna

In the event of a malfunction in the multifunction antenna (e.g. defective because of a rollover), 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.

In vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the voice output takes place via the center instrument panel speaker. In vehicles except CODE 810 (Sound system) and CODE 811 (Advanced sound system), the voice output takes place via the emergency call speaker. Each speaker is actuated via direct lines from the emergency call system control unit.

For all other applications (e.g. audio mode) the speaker system is muted by a mute signal from the emergency call system control unit via a direct line to the sound system amplifier control unit (with CODE 810 (Sound system) or CODE 811 (Advanced sound system)) or to the COMAND controller unit (except CODE 810 (Sound system) and CODE 811 (Advanced sound system)). Normally, the voice connection is terminated by the Service Center or by the driver.

In the event of an emergency call the voice connection can only be terminated by the Service Center.

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 

The emergency call system control unit uses the satellite-supported global positioning system (GPS) to find its location. GPS is available worldwide. The GPS satellites permanently transmit time and position data (longitude and latitude).

GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). Relocation with GPS (after interruption of satellite reception) may require several minutes (up to t = 20 min. when emergency call system control unit is operated for the first time). 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 

Basic position finding 

• Circuit 15R ON or activation of an authorized service

GPS position finding 

The GPS receiver integrated in the emergency call system control unit receives the GPS signals either directly via the multifunction antenna or, in vehicles with CODE 512 (COMAND APS with DVD changer), via the Global Positioning System antenna splitter.

The GPS signals are used by the emergency call control unit to calculate the current vehicle position (receiver).

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

For basic position finding, the emergency call control unit requires the following information:

• Wheel speed signals
• Direction of travel data (forwards or backwards)
• Distance traveled data

The wheel speed signals and the direction of travel are transmitted to the emergency call system control unit by the Electronic Stability Program control unit via the following route:

• Chassis CAN 1
• Electronic ignition switch control unit
• Diagnostic CAN

The distance traveled data is received by the emergency call system control unit from the instrument cluster via the following route:

• Interior CAN
• Electronic ignition switch control unit
• Diagnostic CAN

After this the emergency call system control unit uses the distance traveled, the vehicle alignment and the direction of travel to calculate the vehicle position (degree of longitude and degree of latitude) at any given time.

Error during 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 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 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 crash information via a direct line as a digital crash signal from the supplemental restraint system control unit.

The emergency call system control unit also (redundantly) receives the crash information, including crash level, via the following route:

• Chassis CAN 1
• Electronic ignition switch control unit
• Diagnostic CAN

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 t = 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

Improper actuation of a manual or automatic emergency call is punishable by law.

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 COMAND controller 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 

Actuation of the emergency call system button with the inscription "SOS" for at least 2 seconds actuates the manual emergency call. 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 emergency call system control unit reads in the signals from the emergency call system button via the following path:

• Overhead control panel control unit
• Roof LIN
• SAM control unit
• Interior CAN
• Electronic ignition switch control unit
• Diagnostic CAN

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 emergency call system control unit receives the crash signal (redundant) and the crash level from the Supplemental Restraint System control unit via the following route:

• Chassis CAN 1
• Electronic ignition switch control unit
• Diagnostic CAN

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 into the emergency call system control unit transmits and receives the mobile phone signals via the following route:

• Direct line
• Multifunction antenna

In the event of a manual or automatic emergency call, other vehicle-related services (e.g. MB Info call) are interrupted.

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 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:

• 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 detection

("Flash lights and sound horn")

The four services with the highest priority are listed below.

Priority service

1. Automatic emergency call
2. Manual emergency call
3. Breakdown assistance
4. MB-Info

	Electrical function diagram for status display of emergency call system function		PE82.95-P-2061-97NAA
	Electrical function diagram for manual or automatic emergency call function		PE82.95-P-2066-97NAA
	Electrical function diagram for voice connection between vehicle and Service Center function		PE82.95-P-2069-97NAA
	Electrical function diagram for position finding function		PE82.95-P-2070-97NAA
	Overview of system components, telematics		GF82.85-P-9999GR
	Additional telematics services function		GF82.95-P-2025GRV