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Emergency Call System, Function - GF82.95-P-0004CE

MODEL 204.0/2/3/9 as of model year 2013 with CODE 347 (Ecall emergency call system, Europe) without CODE 348 (Emergency call/assistant system) 

Fig 1: Emergency Call System Block Diagram
G10084768Courtesy of MERCEDES-BENZ USA

Function requirements, emergency call system, general 

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 COMAND controller unit. If necessary, the Mercedes-Benz Service Center notifies the local rescue services.

If the COMAND controller unit receives the "Circuit 15R" message from the electronic ignition lock control unit via the interior CAN, the COMAND controller unit checks the operational readiness of the emergency call system.

The system readiness test lasts a few seconds. If the test is successful, the emergency call system is then ready for operation. At the same time, "SOS ready" is displayed in the telephone menu on the Audio/COMAND display.

The following checks are carried out:

IMPORTANT In the event of a fault, a fault message appears on the Audio/COMAND display, depending on the fault type. Depending on the type of fault, the fault is also stored in the fault memory of the COMAND controller unit.

The emergency call system function comprises the following subfunctions:

IMPORTANT An automatically triggered emergency call has priority via a manually triggered emergency call.

Display of emergency call system status 

The status of the emergency call system is indicated by a text message on the Audio/COMAND display in the following cases:

The COMAND controller unit sends the text messages via a low voltage differential signaling (LVDS) line via AMG Performance Media control unit (model 204.0/2/3 with code (255) AMG Performance Media) to the Audio/COMAND display.

Additional function requirements for voice connection between vehicle and Mercedes-Benz Service Center 

Voice connection between vehicle and Mercedes-Benz Service Center 

Once the emergency call has been triggered, a voice connection with the Mercedes-Benz Service Center is established. The COMAND controller unit mutes the audio sources and interrupts any telephone call that may be in progress. 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 COMAND controller unit and transmitted in the telegram. The hands-free system microphone, which is integrated into the inside rearview mirror (A67), is used for voice commands. The signals from the hands-free system microphone are transmitted to the COMAND controller unit via a direct line.

The COMAND controller unit transmits the signals of the hands-free system microphone to one of the following components via the Bluetooth antenna:

On vehicles with code (386) Mobile phone, the Bluetooth module (up to 31.5.2013) or the mobile phone contact plate (as of 1.6.2013) sends the signals to the Mercedes-Benz Service Center via the following route:

IMPORTANT The mobile phone contact plate (with code (386) Mobile phone as of 1.6.2013) receives the signals via mobile phone cradle (accessories) from the mobile phone.

On vehicles with code (379) Telephone module with Bluetooth SAP, the telephone module with Bluetooth® (SAP profile) sends the signals as follows to the Mercedes-Benz Service Center:

For voice output the COMAND controller unit on vehicles with code (810) Sound system routes the signals received from the Mercedes-Benz Service Center over MOST to the sound system amplifier control unit. In vehicles except code (810) Sound system the COMAND controller unit emits the received signals over the speaker system.

IMPORTANT More detailed information on the speaker system is available in the "Speaker output function" document.

In a normal case, the voice connection is terminated by the Mercedes-Benz Service Center or the user.

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

IMPORTANT In the event of multifunction antenna failure (e.g. defective due to rollover), the antenna of the mobile phone is also used on vehicles with code (386) Mobile phone (except code (379) Telephone module with Bluetooth SAP).

Additional function requirements for data from supplemental restraint system control unit 

Data from supplemental restraint system control unit 

In the event of an accident with airbag deployment, an emergency call is automatically sent out immediately. An emergency call is sent out regardless of the severity of the accident. The COMAND controller unit receives the crash information, incl. crash level as follows from the supplemental restraint system control unit:

IMPORTANT The supplemental restraint system control unit sends a readiness signal cyclically (e.g. every 500 ms) over the same path as for the crash information. In this way, the COMAND controller unit monitors the communication with the supplemental restraint system control unit and the correct operation of the crash detection.

Manual or automatic emergency call 

In an emergency situation, a service receptionist from the Mercedes-Benz Service Center can obtain an overview of the status inside the vehicle with the aid of the data received from the emergency call system control unit (voice connection and data telegram) and initiate appropriate help measures. An emergency call be initiated manually or automatically. These emergency calls are made for the following reasons:

The manual or automatic emergency call function consists of the following subfunctions:

Function sequence for activating an automatic emergency call 

In the event of an accident with airbag deployment, an emergency call is automatically sent out immediately. An emergency call is sent out regardless of the severity of the accident. The COMAND controller unit receives the crash information, incl. crash level as follows from the supplemental restraint system control unit:

An automatic emergency call is also triggered (redundant) if the COMAND controller unit receives the "central locking emergency opening" signal and the cyclic readiness signal ("sign of life") from the supplemental restraint system control unit is not received.

IMPORTANT The supplemental restraint system control unit sends a readiness signal cyclically (e.g. every 500 ms) over the same path as for the crash information. In this way, the COMAND controller unit monitors the communication with the supplemental restraint system control unit and the correct operation of the crash detection.

The "Central locking emergency opening" signal is received by the COMAND controller unit via the interior CAN from the front SAM control unit with fuse and relay module.

Additional function requirements for triggering a manual emergency call 

Function sequence for activating a manual emergency call 

The manual emergency call is initiated by selecting the emergency call address book entry. The address book of the COMAND controller unit can be opened in the Telephone menu. The emergency call address book entry ("Mercedes-Benz Emergency Call") is in first position.

The reserved emergency call address book entry is selected using one of the following operating options:

IMPORTANT Additional information on setting up connections via entries in the address book can be found in the document entitled "Mobile telephone system functionality".

Function sequence for transmission of emergency call data and communication with the Mercedes-Benz Service Center 

Once a manual or automatic emergency call has been triggered, the COMAND controller unit 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:

As soon as a connection to the mobile phone and the mobile telephone network has been established, the COMAND controller unit automatically transmits two text messages using Message Access Profile (MAP) to the Mercedes-Benz Service Center. The text messages contain the following information:

Once the text messages have been transmitted, the voice connection is set up. The COMAND controller unit first transmits a shortened data telegram using the Dual tone multiple frequency (DTMF) procedure via the voice connection. Then the user is contacted by a service receptionist from the Mercedes-Benz Service Center.

The user can terminate the emergency call by pressing the "END" button on the COMAND controller unit or the accept/terminate phone call button (S111s3) in the relevant sub-field.

IMPORTANT During an automatic emergency call the "END" button and the accept/terminate phone call button are temporarily disabled while the connection is being set up in order to avoid unintentional termination. Pressing the "END" button or the Accept/terminate phone call button 2 times briefly in succession can interrupt the automatic emergency call.

Prioritization 

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 (text message or DTMF) containing updated position information is transmitted to the Mercedes-Benz Service Center, and the existing connection is maintained.

  Electrical function diagram for manual or automatic emergency call, function MODEL 204.0/2/3/9 as of model year 2014 with CODE 347 (Ecall emergency call system, Europe) without CODE 348 (Emergency call/assistant system) PE82.95-P-2066-97FAC
MODEL 204.0/2/3/9 as of model year 2013 up to model year 2014 with CODE 347 (Ecall emergency call system, Europe) without CODE 348 (Emergency call/assistant system) PE82.95-P-2066-97FAB
  Overview of system components, telematics   GF82.85-P-9999CE