P82.95-3056-79
Block diagram |
A1 | Instrument cluster | N10/8 | Rear control unit | S111 | Right multifunction steering wheel button group | ||
A2 | Radio (with code 505 (Radio 20 NTG5 without navigation capability) or with code 522 (Audio 20 radio)) | N30/4 | Electronic Stability Program control unit | CAN A | Telematics CAN | ||
A2/5 | Global positioning system antenna splitter | N40/3 | Sound system amplifier control unit (with code 810 (Sound system) or code 811 (Advanced sound system)) | CAN B | Interior CAN | ||
A2/52 | Emergency call system antenna | N70 | Overhead control panel control unit | CAN D | Diagnostic CAN | ||
A28/11 | Multifunction antenna | N73 | Electronic ignition switch control unit | CAN E1 | Chassis CAN 1 | ||
A40/3 | COMAND controller unit (with code 531 (COMAND APS)) | N80 | Steering column module control unit | CAN E2 | Chassis CAN 2 | ||
A40/8 | Audio/COMAND display | N123/4 | Emergency call system control unit | LIN B13 | Roof LIN | ||
A67b1 | Hands-free system microphone group | N135 | Steering wheel electronics | LIN E1 | Steering LIN | ||
H4/27 | Center instrument panel speaker | S93/3s2 | Emergency call system button | LVDS | Low voltage differential signal | ||
N2/10 | Supplemental restraint system control unit | S93/3s4 | Breakdown assistance button | MOST | Media Oriented System Transport | ||
N10 | SAM control unit | S93/3s5 | MB-Info button |
Function requirements, emergency call system, general
Circuit 30
Transport mode not active
Each vehicle-related service is authorized separately.
The communication module of the emergency call system control unit is configured with the telephone number of the relevant service provider.
The vehicle owner is registered and authorized at the Service Center.
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")
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. navigation 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-diagnosis
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
Further subfunctions are described in separate documents:
Additional telematics services function
Internet connection function
The Internet connection is not controlled through the emergency call system control unit, but rather through the audio equipment. Information on prioritization of services will be provided at the end of this document.
Self-diagnosis
If the emergency call system control unit receives the "Circuit 15R" message from the electronic ignition lock control unit, the emergency call system control unit performs a self-diagnosis (approx. 8 to 10 s). The light-emitting diodes of the emergency call system button, the MB-Info button and the breakdown assistance button are on for approx. 10 s.
The emergency call system control unit receives the "Circuit 15R" message via the diagnostic CAN from the electronic ignition lock control unit. After a successful self-diagnosis, the emergency call system is operational and the light-emitting diodes go out.
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.
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-diagnosis, light-emitting diodes light up for approx. 10 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.
Diagnosis
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 lock control unit
Interior CAN
SAM control unit
Roof LIN
Overhead control panel control unit
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 message is displayed in the instrument cluster by the emergency call system control unit in the following way:
Diagnostic CAN
Electronic ignition lock 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 window (with confirmation prompt) on the Audio/COMAND display.
The message or the pop-up window is displayed by the emergency call system control unit via the following route:
Diagnostic CAN
Electronic ignition lock control unit
Interior CAN
Audio equipment
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 over 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 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 user can speak to a service receptionist via the existing voice connection.
The hands-free system microphone group is used for voice input. The signals of the hands-free system microphone group are transmitted to the audio equipment, where they are looped through and forwarded to the communications module integrated in the emergency call system control unit. The communications module integrated in the emergency call system control unit then transmits the hands-free system microphone group 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.
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.
The establishment of a voice connection to the Service Center is interrupted by the communication module integrated into the emergency call system control unit after several unsuccessful dialing attempts. The cancellation of the connection setup is indicated by a corresponding message in the instrument cluster as well as on the Audio/COMAND display. Voice output takes place exclusively via the center instrument panel speaker. The center instrument panel speaker is controlled by the emergency call system control unit via direct lines. The center instrument panel speaker and all other speakers installed depending on the equipment are muted by means of a mute signal from the emergency call system control unit for all other applications (e.g. audio mode).
In vehicles except code 810 (Sound system) and except code 811 (Advanced Sound System), the mute signal is sent to the audio equipment over a direct line. In vehicles with code 810 (Sound system) or code 811 (Advanced sound system), the mute signal is sent over a direct line to the sound system amplifier control unit. Normally, the voice connection is terminated by the Service Center or by the user.
With an emergency call, the voice connection can only be terminated by the Service Center or by ending the telephone connection pressing the right multifunction steering wheel button group for at least 15 s.
Position finding
The emergency call system control unit uses the satellite-supported global positioning system (GPS) to find its location. GPS is available worldwide. GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). Relocating with GPS (after interruption of satellite reception) may require several minutes (up to 20 min. when emergency call system control unit is commissioned). 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 multifunction 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 wheel speed and yaw rate signals from the Electronic Stability Program control unit are transmitted via the following route:
Chassis CAN 1
Electronic ignition lock control unit
Diagnostic CAN
Emergency call system control unit
The emergency call system control unit uses the data to calculate the current vehicle position (longitude and latitude).
Location errors in 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 crash information, including the crash level, is also (redundantly) transmitted 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
For a manual or an automatic emergency call, the Service Center can transfer the data for navigation to the vehicle if required. The data is made available to the navigation module of the audio equipment.
With an emergency call, the voice connection can only be terminated by the Service Center or by ending the telephone connection pressing the right multifunction steering wheel button group for at least 15 s.
The signal is transmitted from the right multifunction steering wheel button group via the following route:
Steering wheel electronics
Steering LIN
Steering column tube module control unit
Chassis CAN 1
Electronic ignition lock control unit
Chassis CAN 2
Instrument cluster
The signal of the right multifunction steering wheel button group is transmitted via the following route by the instrument cluster:
Interior CAN
Electronic ignition lock control unit
Diagnostic CAN
Emergency call system control 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
The manual emergency call is triggered by pressing the emergency call system button. 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 overhead control panel control unit sends the signals from the emergency call system button via the following route:
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 to the Service Center via the integrated communications module.
The SMS automatically sent to the Service Center contains the following data:
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.
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 if one of the four services with the highest priority is activated by SMS 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 data recording for remote diagnosis has its own data channel and it can be conducted in addition to any 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 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 |
MB-Info and breakdown assistance can be converted into a higher priority service by pressing the button of this higher priority service without the voice connection being interrupted. An MB-Info call is converted to a manual emergency call, for example, if the emergency call system button is pressed during an active MB-Info call.
Electrical function diagram for status display of emergency call system function | |||
Electrical function diagram for manual or automatic emergency call function | |||
Electrical function diagram for voice connection between vehicle and Service Center function | |||
Electrical function diagram for position finding function | |||
Additional telematics services function | |||
Overview of system components, telematics |
Referenced documents
- gf8285p9999gn Overview of system components, telematics
- gf8295p2025gnu Additional telematics services function