Emergency call system, function

P82.95-3037-79

Function requirements, emergency call system, general

 Circuit 30

 Transport mode not active

 A mobile phone or a telephone module with Bluetooth® (SAP) (with code 379 (Telephone module with Bluetooth® (SAP))) is connected via Bluetooth® to the COMAND controller unit.

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 over the user interface CAN, the COMAND controller unit checks the operational readiness of the emergency call system.

The following checks are carried out:

 Receipt of cyclic readiness signal ("sign of life") from the Supplemental Restraint System control unit

 Operating capability of the SOS button

 Availability of a mobile phone or telephone module with Bluetooth® (SAP profile) connected to the COMAND controller unit via Bluetooth®

The LED of the SOS button illuminates for approx. 5 s. After successful checking, the emergency call system is operational and the LED goes off. At the same time, "SOS ready" is displayed in the telephone menu on the audio/COMAND display.

 In the event of a fault, depending on the type of fault a fault message appears on the audio/COMAND display and the LED of the SOS button is permanently actuated. 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:

 Emergency call system status indication

 Voice connection between vehicle and Mercedes-Benz Service Center

 Data from the supplemental restraint system control unit

 Manual or automatic emergency call

 An automatically triggered emergency call has priority via a manually triggered 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

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. 5 s.

 Emergency call has been triggered, LED flashes.

 Fault in emergency call system, LED on permanently.

 Emergency call system ready for operation, LED is off.

The COMAND controller unit actuates the LED via the following route:

User interface CAN 

Electronic ignition lock control unit 

Interior CAN 

Front SAM control unit 

Roof LIN 

Overhead control panel control unit 

SOS button

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 is operational ("SOS ready" in "Telephone" menu).

 Emergency call has been activated ("activating" (call setup), "sending data" (data telegram transmission), "connected" (voice connection established)).

 Fault in emergency call system

The COMAND controller unit sends the text messages over a low voltage differential signaling line to the Audio/COMAND display.

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

 Manual or automatic emergency call triggered.

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 rear-view 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. For voice output, in vehicles with CODE 810 (Sound system) or CODE 811 (Advanced sound system), the COMAND controller unit forwards the signals received from the Mercedes-Benz Service Center to the sound system amplifier control unit via MOST. In vehicles except CODE 810 (Sound system) and CODE 811 (Advanced sound system), the COMAND controller unit outputs the received signals via the speaker system.

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

 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 COMAND controller unit sends the signals of the hands-free system microphone to one of the following components via the Bluetooth® antenna:

 Telephone module with Bluetooth® (SAP profile) (with code 379 (Telephone module with Bluetooth® (SAP profile)))

 Mobile phone

The signals can be transferred to the Service Center in various ways.

If the telephone module with Bluetooth® (SAP profile) (with code 379 (Telephone module with Bluetooth® SAP profile)) or the mobile phone communicates with the mobile phone contact plate (with code 386 (Convenience telephony)), the signals are transmitted by the communication device to the Service Center via the following route:

Mobile phone cradle (accessory, except code 379 (Telephone module with Bluetooth® (SAP profile))) 

Mobile phone contact plate 

Cellular telephone system antenna amplifier/compensator 

Mobile phone and stationary heater radio remote control antenna splitter (with code B24 (Remote control for stationary heater)) 

Multifunction antenna

If the telephone module with Bluetooth® (SAP profile) (with code 379 (Telephone module with Bluetooth® SAP profile)) or the mobile phone communicates with the rear mobile phone contact plate (with code 856 (Business Telephony in the rear)), the signals are transmitted by the communication device to the Service Center via the following route:

Rear mobile phone cradle (accessory, except code 379 (Telephone module with Bluetooth® (SAP profile))) 

Rear mobile phone contact plate 

Rear cellular telephone system antenna amplifier/compensator 

Multifunction antenna

The COMAND controller unit transmits the switch-on signal (wake-up signal) via the Rear Seat Entertainment system controller unit (with CODE 864 (Rear entertainment system)) to the rear mobile phone contact plate (with CODE 856 (Business telephony in rear)).

 Model 222
with code 347 (Mercedes-Benz emergency call system)
with code 856 (Business telephony in rear passenger compartment)
with code 864 (Rear compartment entertainment package)
except code 348 (Emergency call/assistant system)
except code 350 (Ecall emergency call system, Europe)
The rear mobile phone contact plate is switched on via the Rear Seat Entertainment system controller unit.

 Model 222
with code 347 (Mercedes-Benz emergency call system)
with code 386 (Comfort telephony)
with code 856 (Business telephony in rear passenger compartment)
except code 348 (Emergency call/assistant system)
except code 350 (Ecall emergency call system, Europe)
In case of multifunction antenna failure (e.g. defective due to vehicle rollover), the antenna of the mobile phone is also used.

If the mobile phone does not communicate with either the mobile phone contact plate (with CODE 386 (Comfort telephony)) or with the rear mobile phone contact plate (with CODE 856 (Business telephony in rear)), the mobile phone transmits the signals directly to the mobile telephone network.

Additional function requirements for data from 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 is immediately sent out. An emergency call is sent out regardless of the severity of the accident. The COMAND controller unit receives the crash information, including the crash level, from the supplemental restraint system control unit over the user interface CAN.

 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 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:

 Automatic alerting of the rescue services after an accident

 Alerting rescue services by pushing a button (own emergency situation, observed accident)

 Reduction of rescue times by means of fast emergency notification with details about exact location

The emergency call consists of the following processes:

 Function sequence for activating an automatic emergency call

 Function sequence for activating a manual emergency call

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

Additional function requirements for triggering an automatic emergency call

 Ignition ON (circuit 15R) (with ignition OFF, "Ecall not ready" appears on the display)

Function sequence for activating 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 COMAND controller unit receives the crash information, including the crash level, from the supplemental restraint system control unit over the user interface CAN.

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.

The "Central locking emergency opening" signal is sent by the front SAM control unit via the following route:

Interior CAN 

Electronic ignition lock control unit 

User interface CAN 

COMAND control unit

 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 COMAND controller unit monitors the communication with the supplemental restraint system control unit and the correct operation of the crash detection.

Additional function requirements for triggering a manual emergency call

 No automatic emergency call is active.

 A manual emergency call can also be made with ignition OFF.

Function sequence for activating a manual emergency call

A manual emergency call can be triggered in two different ways:

 Press SOS button

 Select emergency call address book entry

Press SOS button

The manual emergency call is triggered by pressing the SOS button marked "SOS". 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 signals of the SOS button are read in via the following route:

Overhead control panel control unit 

Roof LIN 

Front SAM control unit 

Interior CAN 

Electronic ignition lock control unit 

User interface CAN 

COMAND control unit

Select 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:

 Audio/COMAND control panel: Telephone button, Audio/COMAND controller

 Left multifunction steering wheel button group: Scroll forward/back button, system selection button, "Back" button, OK button.

 Telephone keypad (except code 448 (Touchpad))

 Telephone keypad (with CODE 448 (Touchpad))

 Voice control system

 Remote control (with code 816 (Entertainment remote control) or with code 867 (SPLITVIEW))

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:

 "Activating" (setting up the call)

 "Transmitting data" (transmission of emergency call data (data telegram))

 "Connected" (voice connection established)

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:

 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 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 end the emergency call by pressing the "Terminate conversation" button on the telephone keypad or using the accept/terminate phone call button on the multifunction steering wheel in the corresponding subfield.

 During an automatic emergency call the "Terminate conversation" button and the accept/terminate phone call button on the multifunction steering wheel are temporarily disabled while the connection is being set up in order to avoid unintentional termination. Pressing the "Terminate conversation" 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 (SMS or DTMF) containing updated position data is sent to the Mercedes-Benz Service Center, and the existing connection is maintained.