Emergency Contact Button: Description and Operation

GF82.95-P-3212FLU Emergency Call System Control Unit, Component Description
- with CODE (359) TELE AID emergency call system

Component Identification:

Location
The emergency call system control unit is located in the trunk under the trunk mat on the crossmember.

Task
^ Realization of vehicle-related services
^ Regulation of priorities over integrated priority management
^ Communication management between vehicle and Service Center
^ Forwarding vehicle position and identification as well as other required data to the Service Center
^ Audio management
^ Display management
^ Treatment of fault
^ Receive signals
^ Transmitting signals

Realization of vehicle-related services
Realization of following vehicle-related services:
- Authorization
- Manual or automatic emergency call, including police emergency call number " 911"
- MB information call
- Roadside assistance
- Vehicle tracking
- Vehicle remote unlocking
- Vehicle remote locking

Regulation of priorities via integrated priority management

Priority Service
1 Automatic alarm call
2 Manual emergency call
3 Vehicle tracking
4 Roadside assistance
5 MB information call
6 Authorization
7 Vehicle remote door unlock or vehicle remote door lock

Communication management between vehicle and Service Center
Communication management between vehicle and Service Center over integrated communication module and national mobile telephone network as well as transmission of information to driver if required.

Forwarding vehicle position and identification as well as other required data to the Service Center
- Forwarding vehicle position and identification as well as other required data to the Service Center after activation by the following actions:
- Crash signal from supplemental restraint system control unit (N2/10), for automatic emergency call
- Actuation of emergency call system button (S93/3), for manual emergency call
- Actuation of MB-Info button (S93/6s1), for MB-Info call
- Actuation of breakdown assistance button (S93/6s2), for breakdown assistance
- Call to the Service Center and actuation of the trunk lid external operation switch (S88/8) (model 212.0) or liftgate external operation switch (S88/8) (model 212.2), for vehicle remote door unlock
- Call to Service Center and reporting of theft for vehicle tracking

Audio management
- Output of audio signals via center dashboard speaker (H4/27)
- Audio muting (MUTE)

Display management
- Management of displays on the Audio/COMAND display (A40/8), instrument cluster (A1), emergency call system button, MB-Info button and breakdown assistance button

Treatment of fault
After activation of circuit 15R, the emergency call system control unit performs a self-test (for approx. t = 4 s). If the self-test is successful, the emergency call system is then ready for operation. 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 emergency call system button are permanently actuated. Depending on the fault type, the fault is also stored in the emergency call system control unit's memory.

Receive signals
^ Direct lines
^ Controller Area Network (data bus/CAN bus) (CAN)

Direct lines
- Power supply over circuit 30g and circuit 31
- Status signal c. 15R
- Emergency call system button signa
- MB info button signal
- Breakdown assistance button signal via a direct line
- Crash signal from supplement restraint system control unit
- Signal from handsfree system microphone (A67b1) via COMAND control unit (A40/3)
- Mobile telephone signals from multifunction antenna (A28/11) via coaxial cable
- Global positioning system (GPS) signals from multifunction antenna via global positioning system antenna splitter (A2/5) (with code (512) COMAND APS incl. DVD changer)
- Mobile phone signals from emergency call system antenna (A2/52)

CAN
The emergency call system control unit is a subscriber of the diagnostic CAN (CAN D). The emergency call system control unit receives the crash data from the supplemental restraint system control unit and also (redundantly), including crash level, via the following route:
- Chassis CAN (CAN E)
- Front SAM control unit with fuse and relay module (N10/1)
- Diagnostic CAN

Transmitting signals

Direct lines
- Voice output via center instrument panel speaker
- Actuating signal for LED in emergency call button
- Actuating signal for LED in MB Info button
- Actuating signal for LED in breakdown assistance button
- Audio muting to following control unit:
- Sound system amplifier control unit (N40/3) (with code (810) Sound system)
- COMAND control unit (without code (810) Sound system)

- Mobile phone signals to multifunction antenna via coaxial cable
- Wake-up signal to COMAND control unit
- Mobile phone signals to emergency call system antenna

Design
- Integrated communication module
- 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
- Screened metal housing

Function
The emergency call system control unit has its own microprocessor. A differentiation is made between the subareas of the communication module with NAD and the locating module. The emergency call system control unit centrally processes all the vital data for the listed vehicle-related services.

The emergency call system control unit uses the installed locating module to calculate the vehicle position and generates a data telegram in the form of an SMS when one of the following vehicle-related services has been activated:
- Manual or automatic emergency call, including police emergency call number " 911"
- MB information call
- Roadside assistance
- Vehicle remote unlocking

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 over mobile phone frequencies. This supports communication via the two American mobile telephone networks: the analog Advanced Mobile Phone Service (AMPS) network and the digital Code Division Multiple Access (CDMA) network. For data communication in the AMPS network, the communication module also uses a modem.

AMPS and CDMA network properties:
- CDMA Class 3,: f = 800 MHz with P = 0.2 W transmitter output
- CDMA Class 2,: f = 1900 MHz with P = 0.1 W transmitter output
- AMPS f = 800 MHz
- SMS

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 activated (wake-up); after four days the emergency call system reverts to the "sleep mode"
- Following activation a self-diagnosis is performed and the result sent to the "controller"

In the event of a multifunction antenna malfunction (e.g. defective because of rollover) the emergency call system control unit automatically uses the emergency call system antenna to transmit mobile phone signals.