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(Component Description For Emergency Call System Control Unit - GF82.95-P-3212RFU)

Model 205, 253 up to model year 2017 with code 348 (Emergency call/assistant system) 

Shown: Model 205.0 

G14187961Courtesy of MERCEDES-BENZ USA

Shown: Model 253.9 

G14187962Courtesy of MERCEDES-BENZ USA

Location 

In model 205.0/2/3 except hybrid vehicles, the emergency call system control unit is located beneath the paneling in the trunk, in the front area behind the rear bench seat. On the model 205.047 hybrid vehicles, the emergency call system control unit is installed on a major assembly carrier in a recess under the paneling of the trunk in the rear area slightly to the right of center.

On model 253.9 vehicles, the emergency call system control unit is installed in the center console.

Tasks 

Realization of vehicle-related services 

The emergency call system control unit enables the following vehicle-related services to be realized:

IMPORTANT The Internet connection is not controlled through the emergency call system control unit, but through the head unit (A26/17).

IMPORTANT The emergency call system control unit is not used for regular telephone calls.

IMPORTANT Via the mobile radio connection to the Service Center the emergency call system control unit also receives the trigger signal for the "Remote Start" function (for pre-entry climate control) which the customer transmits via the mobile phone to the service provider. The "Remote Start" function starts the engine on a parked and locked vehicle (windows and doors closed), and after a limited period it switches it off again, to enable the "Load Mode" to achieve a pre-entry climate control of the A/C system. The emergency call system control unit forwards the triggering signal via the diagnostic CAN (CAN D) to the electronic ignition lock control unit (N73).

Implementation of specific services for hybrid vehicles 

The emergency call system control unit enables the following vehicle-related services to be realized:

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 SMS capability are:

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 

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 

After activation of circuit 15R, the emergency call system control unit performs a self-diagnosis. 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 

The emergency call system control unit receives the following signals over direct lines:

Seat occupied recognition LIN 

The emergency call system control unit receives the crash signal over the seat occupancy LIN from the supplemental restraint system control unit (N2/10).

CAN 

The emergency call system control unit is a diagnostic CAN subscriber. The emergency call system control unit receives the following signals, for example, via the diagnostic CAN from the electronic ignition lock control unit:

Radio interface for wireless local area network (WLAN) (with CODE 531 (COMAND APS)) 

The emergency call system control unit receives radio signals for Internet communication, which the head unit transmits over the WLAN antenna (A2/83).

Integrated Bluetooth® interface (except CODE 531 (COMAND APS)) 

The emergency call system control unit receives Bluetooth® signals for Internet communication that the head unit transmits via the Bluetooth® antenna (A2/91).

Transmitting signals 

Direct lines 

The emergency call system control unit transmits the following signals:

CAN 

The emergency call system control unit transmits the following signals:

Integrated radio interface for wireless local area network (WLAN) (with CODE 531 (COMAND APS)) 

The emergency call system control unit transmits Internet data as radio signals to the WLAN antenna.

Integrated Bluetooth® interface (except CODE 531 (COMAND APS)) 

The emergency call system control unit transmits Internet data as Bluetooth® signals to the Bluetooth® antenna.

Body 

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 

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 communications module are:

IMPORTANT If reception is poor or if the left telephone antenna (A2/102) and right telephone antenna (A2/103) fail (e.g. they are defective due to a rollover or side impact), the emergency call system control unit automatically uses the emergency call system antenna for receiving and sending mobile radio signals.

  Wiring diagram for emergency call system control unit   PE82.95-P-2101-97FBA