(Component Description For Emergency Call System Control Unit - GF82.95-P-3212LFU)
Model 217, 222
up to model year 2017
with code 348 (Emergency call/assistant system)
Shown on model 222.0
Location
The emergency call system control unit is located behind the left rear seat backrest on the module's rear panel.
Tasks
- Realization of vehicle-related services
- Regulation of priorities via integrated priority management
- Communication management between vehicle and service center
- Audio management
- Display management
- Error handling
- Receive signals
- Transmitting signals
Realization of vehicle-related services
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")
- 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 recognition ("Flash Lights and Sound Horn")
- Internet connection
The Internet connection is not managed through the emergency call system control unit, but rather through the COMAND controller unit (A40/3).
The emergency call system control unit is not used for regular telephone calls.
Regulation of priorities via integrated priority management
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 short message service (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 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 |
Communication management between vehicle and service center
The emergency call system control unit controls communication between the vehicle and the Service Center via the integrated communication module and the mobile telephone network, and establishes a voice connection with the driver if necessary. In many cases (e.g. breakdown assistance, MB Info call) the connection setup with the Service Center also includes the transmission of an SMS containing the vehicle position, identification data and other vehicle data ("Initial Summary").
Audio management
- Output of audio signals over the center instrument panel midrange speaker (H4/78) (with CODE 811 (Advanced sound system)) or over the center instrument panel speaker (H4/27) (except CODE 811 (Advanced sound system))
- Muting of audio sources (mute function)
Display management
Management of function-related displays on audio/COMAND display (A40/8), in the instrument cluster (A1), in the SOS button (N70s11), in the breakdown assistance button (N70s12) and in the MB-Info button (N70s13).
Error handling
Following activation of circuit 15R, the emergency call system control unit then runs a self-diagnosis (approx. 8 to 10 s). If the self-diagnosis test is successful, the emergency call system is then operational. In the event of a fault, a fault message is displayed on the instrument cluster depending on the fault type, and the two red light-emitting diodes (LED) in the SOS button are permanently actuated. Depending on the fault type, the fault is also stored in the emergency call system control unit's fault memory.
Receive signals
- Direct lines
- Seat occupied recognition LIN (LIN E2)
- CAN
- Integrated radio interface for wireless local area network (WLAN)
Direct lines
- Power supply via circuit 30 and circuit 31
- Signal from hands-free system microphone (A67b1) over the COMAND controller unit
- Cellular telephone system and Internet signals from the multifunction antenna (A28/11) over a coaxial cable
- Global positioning system (GPS) signals from the multifunction antenna over the global positioning system antenna splitter
- Cellular telephone system and Internet signals from the left emergency call system antenna (A2/54) and the right emergency call system antenna (A2/55) over the emergency call system antenna splitter
Seat occupied recognition LIN
- Crash signal from the Supplemental Restraint System control unit (N2/10)
CAN
The emergency call system control unit is a diagnostic CAN (CAN D) subscriber. The emergency call system control unit receives, e.g. the following signals over the diagnostic CAN from the electronic ignition lock control unit (N73):
- Circuit 15R ON
- Crash information from the Supplemental Restraint System control unit (redundant), including crash level
- Operation of the SOS button, the MB-Info button and the breakdown assistance button
- Rpm signals from the Electronic Stability Program control unit (N30/4)
- Vehicle data (for "Initial Summary")
- Diagnostic data (with remote diagnosis)
Integrated radio interface for wireless local area network (WLAN)
The emergency call system control unit receives radio signals for Internet communication, which the COMAND controller unit transmits via the W-LAN antenna (A2/83).
Transmitting signals
- Direct lines
- CAN
- Integrated radio interface for wireless local area network (WLAN)
Direct lines
- Voice output via center instrument panel speaker
- Muting of audio sources (mute function) to the sound system amplifier control unit (N40/3) (with code 810 (Sound system) or code 811 (Advanced sound system)) or to the COMAND controller unit (except code 810 (Sound system) or code 811 (Advanced sound system))
- Mobile phone signals to multifunction antenna via coaxial cable
- Cellular telephone system signals to the left and right emergency call system antenna via the emergency call system antenna splitter
CAN
- Actuation signal for LEDs in the SOS button, the MB Info button and the breakdown assistance button
- Navigation data and other data transmitted by the Service Center ("Remote Information Feed") to the COMAND controller unit
- Status signals to the COMAND controller unit
- Status signals to the instrument cluster
Integrated radio interface for wireless local area network (WLAN)
The emergency call system control unit transmits Internet data as radio signals to the WLAN antenna.
Body
- Integrated Internet-compatible communications module with radio interface for wireless local area network (WLAN)
- Integrated locating module
- Integrated GPS receiver for position finding (date, time, history and last-known location) for the listed vehicle-related services
- Memory for vehicle-specific data
- Buffer for navigation and other data that is transmitted to the vehicle
- Plastic housing
Function
The emergency call system control unit centrally processes all the vital data for the listed vehicle-related services. The emergency call system control unit has its own microprocessor. A distinction is made between the following subareas:
- Position finding module
- Communications module
Position finding module
The emergency call system control unit uses the installed positioning module to calculate the position of the vehicle and, if necessary, generates a message to the Service Center or a data telegram ("Initial Summary") in the form of an SMS.
Communications module
The communication module integrated into the emergency call system control unit is a mobile phone transceiver enabling voice and data communication with the service center via mobile phone frequencies.
Communication takes place via the digital Code Division Multiple Access (CDMA) network. Other functions of the communication module are:
- Four day transmission and reception capability: As soon as an SMS is received, the emergency call system control unit is also activated (wake-up); after four days the emergency call system goes into "sleep mode".
- After circuit 15 ON a self-diagnosis test is conducted.
As of 01.06.2015 the customer can actuate the "Remote Start" function using the mobile phone through the service provider. The message is received over the vehicle antennas by the emergency call system control unit, and forwarded over CAN to the electronic ignition lock control unit. The vehicle then starts the engine for a limited period of time to permit pre-entry climate control.
In the event of insufficient reception or failure of the multifunction antenna (e.g. defect caused by rollover), the emergency call system control unit automatically uses the left and right emergency call system antenna to receive and send the cellular telephone system signals.
| Wiring diagram for emergency call system control unit | PE82.95-P-2101-97SEA |