Component description for emergency call system control unit - GF82.95-P-3212FLV

MODEL 212 with CODE 348 (Emergency call/assistant system) without CODE 359 (TELE AID emergency call system) 

Shown on model 212.0 with CODE 512 (COMAND APS with DVD changer) 

Fig 1: Emergency Call System Control Unit - Shown On Model 212.0

Courtesy of MERCEDES-BENZ USA

Location 

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

Tasks 

The emergency call system control unit has the following tasks:

• Realization of vehicle-related services 
• Regulation of priorities via integrated priority management 
• Communication management between vehicle and service center 
• Display management 
• Audio 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 antitheft 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. 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 (all vehicles as of 2.3.15; up to 1.3.15 with CODE 512 (COMAND APS with DVD changer) or with CODE 527 (COMAND APS with single DVD drive (with navigation)))

The Internet connection is not controlled through the emergency call system control unit, but rather through the audio equipment.

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 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 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:

• 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.

Communication management between vehicle and service center 

The emergency call system control unit controls communication between the vehicle and the Service Center through the integrated communication module, the antenna connection 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").

In the event of a malfunction in the multifunction antenna (A28/11) or if reception is poor, 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 (A2/52).

Display management 

The emergency call system control unit actuates the function-specific displays in the following components:

• Audio/COMAND display (A40/8)
• Instrument cluster (A1)
• Emergency call system button (S93/3), breakdown assistance button (S93/6s2) and MB-Info button (S93/6s1)

Audio management 

Audio management encompasses the following functions:

• Voice output via center instrument panel speaker (H4/27)
• Audio muting (MUTE)

Error handling 

After activating circuit 15R, the emergency call system control unit performs a self-test (approx. 8 to 10 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 
• CAN 
• Integrated radio interface for wireless local area network (WLAN) (as of 2.3.15 with CODE 531 (COMAND APS)) 
• Integrated Bluetooth® interface (except CODE 531 (COMAND APS)) 

Direct lines 

• Power supply via circuit 30 and circuit 31
• Actuation of the emergency call system button, the MB-Info button, or the breakdown assistance button
• Crash signal from the supplemental restraint system control unit (N2/10)
• Signals from the hands-free system microphone (A67b1) via the audio equipment
• Mobile radio and Internet signals from the multifunction antenna over a coaxial cable
• Mobile radio and Internet signals from emergency call system antenna
• Global positioning system (GPS) signals from the multifunction antenna via the global positioning system antenna splitter (A2/5) (all vehicles as of 2.3.15; up to 1.3.15 with CODE 512 (COMAND APS with DVD changer) or with CODE 527 (COMAND APS with single DVD drive (with navigation)))

CAN 

The emergency call system control unit is a subscriber of the diagnostic CAN (CAN D) and receives e.g. the following signals via this CAN connection from the front SAM control unit with fuse and relay module (N10/1):

• Crash information from the supplemental restraint system control unit (redundant), including crash level
• Wheel speed and yaw rate signals from the Electronic Stability Program control unit (N30/4) (except model 212.095 and except CODE 233 (DISTRONIC PLUS)), the Premium Electronic Stability Program control unit (N30/7) (with CODE 233 (DISTRONIC PLUS)) or the regenerative braking system control unit (N30/6) (model 212.095)
• Vehicle data (for "Initial Summary")
• Diagnostic data (with remote diagnosis)

Integrated radio interface for wireless local area network (WLAN) (as of 2.3.15 with CODE 531 (COMAND APS)) 

The emergency call system control unit receives radio signals for Internet communication which are sent by the COMAND controller unit (A40/3) over the WLAN antenna (A2/83).

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

The emergency call system control unit receives Bluetooth® signals for the Internet communication, which are sent by the radio (A2) (as of 2.3.15, with CODE 522 (Audio 20 radio)) or the COMAND controller unit (up to 1.3.15, with CODE 512 (COMAND APS with DVD changer) or with CODE 527 (COMAND APS with single DVD drive (with navigation))) via the Bluetooth antenna (A2/91).

Transmitting signals 

• Direct lines 
• CAN 
• Integrated radio interface for wireless local area network (WLAN) (with CODE 531 (COMAND APS)) 
• Integrated Bluetooth® interface (except CODE 531 (COMAND APS)) 

Direct lines 

The emergency call system control unit transmits the following signals via direct lines:

• Voice output via center instrument panel speaker
• Audio muting (MUTE) to the sound system amplifier control unit (N40/3) (with CODE 810 (Sound system) or CODE 811 (Advanced sound system))
• Audio muting (MUTE) to the audio equipment (except CODE 810 (Sound system) and except CODE 811 (Advanced sound system))
• Mobile radio and Internet signals to multifunction antenna
• Mobile radio and Internet signals to emergency call system antenna
• Actuation signal for LEDs in the emergency call system button, the MB Info button and the breakdown assistance button

CAN 

The emergency call system control unit sends e.g. the following signals via the diagnostic CAN to the front SAM control unit with fuse and relay module:

• Navigation and other data transmitted by the Service Center ("Remote Information Feed") to the audio equipment
• Status signals to the audio equipment
• Status signals to the instrument cluster

Integrated radio interface for wireless local area network (WLAN) (as of 2.3.15 with CODE 531 (COMAND APS)) 

The emergency call system control unit sends Internet signals to the WLAN antenna.

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

The emergency call system control unit sends Internet signals to the Bluetooth® antenna.

Body 

• Integrated Internet-compatible communication module
• Integrated radio interface
• Integrated Bluetooth® interface
• 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".
• Following circuit 15 ON a self-test is performed.

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 emergency call system antenna to receive and transmit the mobile radio signals.