Preconditions
The service is available in the region you are traveling in.
The emergency call system's self-test was passed.
Manual emergency call: Circuit 30g (model 447.8: Communication module control unit (N161) active)
Automatic emergency call: Circuit 15 (Supplemental Restraint System control unit (SRS) (N2/18) active)
Information on the regional availability of the emergency call is available at: http://www.mercedes-benz-mobile.com/extra/ecall.
The emergency call system is activated ex factory; therefore it only needs to be activated by the user if it was deactivated beforehand.
When the engine has been started, the communications module checks that the emergency call system is ready by means of a self-test. After a successful check, the emergency call system is operational and "SOS ready" is shown in the audio/COMAND display control unit (A40/8). In the case of a fault, a fault message depending on the fault type appears in the audio/COMAND display control unit (A40/8).
The following checks are carried out:
Receipt of cyclical operational readiness signal ("life sign") from SRS control unit
Connection for mute function (muting of audio sources)
Connection to hands-free system microphone (B25/17), from head unit
Connection to emergency call antenna(s)
Connection to GPS antenna (if head unit can not be navigated, global navigation system (GPS))
If the SRS control unit goes into sleep mode after ignition OFF, it no longer transmits an operational readiness signal and "SOS not ready" is shown.
Emergency call system, general
In order to shorten rescue times by reporting the emergency quickly and providing the exact location, the emergency call system allows a manual or automatic emergency call to be triggered. When an emergency call is made, vehicle data are transmitted and a voice connection to the service center is established.
In some markets, connection is established with the public emergency call center when an emergency call is triggered.
The vehicle data are transmitted to the service center in the form of an SMS. In the case of certain conditions of the mobile phone network, a reduced data packet is transmitted via DTMF ("dual-tone multi-frequency"). The following data are transmitted in the SMS:
Vehicle GPS position.
Position history (tracking of vehicle positions up to a distance of a few 100 m from the current location).
Direction of travel based on position history.
Vehicle identification number.
Type of drive in vehicle
Number of vehicle occupants (estimated), only the front seats are registered.
Accident management support
Manual or automatic emergency call
Time stamp
Language (as set on the head unit)
Wherever possible, the user is addressed in the language which is set on the head unit. The audio sources in the vehicle are muted by the communications module to ensure that the dialog is not disturbed. If necessary, the Mercedes-Benz Service Center notifies the local rescue services.
The status of the connection setup is indicated by messages on the display of the head unit.
The following states of the emergency call system are displayed in the Telephone menu in the instrument cluster: active service, error in emergency call system.
During the emergency call, the LED in the SOS button flashes.
If the Mercedes-Benz Service Center is not staffed or is unavailable, the emergency call is automatically forwarded to the local rescue services 112. If the emergency call system is unable to establish a connection, an error message is shown in the display which instructs the user to dial 112 on a mobile phone.
An emergency call that was made by mistake can be ended like a telephone call, e.g. by pressing the terminate phone call button on the multifunction steering wheel. In the case of an automatically triggered emergency call, however, this cannot be done immediately.
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 CAN message with updated position data is transmitted to the Mercedes-Benz Service Center while maintaining the existing connection.
Shown on model 447.8 |
N2/18 | Supplemental restraint system (SRS) control unit |
S91.60-4598-05
Automatic emergency call
In the event of an accident with deployment of the restraint systems (not the PRE-SAFE® system) an automatic emergency call (eCall) is immediately sent. An emergency call is sent out regardless of the severity of the accident.
The communication module receives the crash signal via the vehicle's bus system from the SRS control unit. With the HERMES control unit (N112/9), the crash signal is received via the bus system.
S82.95-4506-09
Shown on model 447.8 |
N70s11 | SOS button | N70s13 | MB Info call button (for model 447.8) | |
N70s12 | Breakdown assistance button (for model 447.8) |
Manual emergency call
The user triggers the manual emergency call by pressing the SOS button. The SOS button is installed at the center above the windshield (either integrated in the overhead control panel control unit (OCP) (N70) or close to the mirror base) and covered by a protective flap. Pressing the protective lid unlocks the lid, and it automatically opens with the aid of a spring mechanism.
More detailed information can be found in the telematics function description.