GF82.95-P-3000CWU Position Finding, Function

GF82.95-P-3000CWU Position Finding, Function
- with CODE (359) TELE AID emergency call system

Position finding function requirements
^ Status "circuit 30 ON", for the Global Positioning System (GPS) position finding or for vehicle tracking
^ Status "circuit 15R ON", for basic position finding or for vehicle tracking
^ Telematic Alarm Identification on Demand (emergency call system) (TELE AID) system authorized and operating error-free
^ No fault on the GPS antenna system and signals from at least 3 GPS satellites, for GPS position finding
^ Faultless communication with the Electronic Stability Program control unit (N30/4)
^ The vehicle-related vehicle tracking service is authorized separately
^ An emergency call system control unit (N123/4) communication module authorized for the corresponding vehicle-related service is configured ex-factory with the telephone number of the corresponding service provider
^ The customer is registered and authorized in the Customer Assistance Center (CAC), for vehicle tracking
^ A mobile telephone network is available in adequate strength and quality, for vehicle tracking
^ Vehicle theft notification and legitimization by the customer per telephone with CAC or the anti-theft alarm system (ATA [EDW]) is active for > 30 s, for vehicle tracking
^ A higher-priority vehicle-related service is not active, for vehicle tracking

Depending on equipment installed one of the following control units is installed:
^ COMAND controller unit (A40/3), with code (512) COMAND APS with DVD changer
^ Radio (A2), with code (494) USA version
^ Radio, with code (510) Audio 20 with CD changer

The function description uses the term "master control unit".

General position finding
For GPS position finding the emergency call system control unit requires the global positioning system, which is a satellite supported positioning system. It is available worldwide. The GPS satellites permanently transmit time and position data (longitude and latitude). 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 following points are vehicle tracking objectives:
^ Retrieval of stolen or misappropriated vehicles
^ Fast assistance in event of a "car jacking"

The position finding function consists of the following subfunctions:
^ GPS position finding function sequence
^ Basic position finding function sequence
^ Vehicle tracking function sequence

GPS position finding function sequence
The GPS receiver integrated into the emergency call system control unit receives the GPS signals from the multifunction antenna (A28/11) in the following way:
^ Discrete line
^ Global positioning system antenna splitter (A2/5), with code (512) COMAND APS with DVD changer
^ Discrete line

The GPS signals are used by the emergency call control unit to calculate the current vehicle position (receiver).
In addition, the vehicle's direction of travel is determined with the aid of the sequence of the locations calculated with GPS.

Basic position finding function sequence
For basic position finding, the emergency call control unit requires the following information:
^ Wheel speed signals
^ Distance traveled data
^ Vehicle alignment (cardinal points)
^ Direction of travel data (forwards or backwards)

The wheel speed signals are recorded by the following rpm sensors:
^ Left front axle rpm sensor (L6/1)
^ Right front axle rpm sensor (L6/2)
^ Left rear axle rpm sensor (L6/3)
^ Right rear axle rpm sensor (L6/4)

The wheel speed signals from the rpm sensors are received by the emergency call system control unit in the following way:
^ Discrete line
^ ESP control unit
^ Chassis CAN
^ Front SAM control unit with fuse and relay module (N10/1)
^ Diagnostic CAN

The distance traveled data from the instrument cluster (A1) is received by the emergency call system control unit in the following way:
^ Interior CAN
^ "Master control unit"
^ Interior CAN
^ Front SAM control unit with fuse and relay module
^ Diagnostic CAN

The vehicle alignment data (cardinal points) is internally processed by the emergency call system control unit's integrated turn rate sensor (gyro sensor).

The direction of travel data (forwards or backwards) is received by the emergency call system control unit via the diagnosis CAN from the front SAM control unit with fuse and relay module.
After this the emergency call system control unit uses the distance traveled, the vehicle alignment and the direction of travel to calculate the vehicle position (degree of longitude and degree of latitude) at any given time.

Error during position finding
Basic position finding is falsified when a vehicle rolls backwards with "circuit 15 OFF" (ignition switched off) or if it is transported somewhere. 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.

Vehicle tracking function sequence
The vehicle tracking function differentiates from the routine type of position finding only through the two following triggering variations; the subsequent function sequence is identical:
^ Vehicle theft notification from customer per telephone to the CAC
^ Anti-theft alarm system active for > 30 s

Vehicle theft notification from customer per telephone to the CAC
Following a theft notification by telephone, the CAC checks the customer's query and legitimization and if the data matches up it issues an initiation command to the vehicle.

Anti-theft alarm system active for > 30 s
If the anti-theft alarm system is triggered, the emergency call system control unit receives an "ATA alarm" message in the following way:
^ Front SAM control unit with fuse and relay module
^ Diagnostic CAN

The initiation command or the "ATA alarm" message is received or sent by the communication module integrated into the emergency call system control unit via the multifunction antenna in the following way:
^ Discrete line
^ Frequency switchover control unit (N96), with code (389) Mobile phone preinstallation with universal interface, USA/ Canada
^ Discrete line

The emergency call system control unit activates the GPS position finding and also the voice connection to the vehicle. Following this, the communication module integrated into the emergency call system control unit sends the position data to the service provider in the same way as the initiation command or "ATA alarm" message. This is done cyclically and for the following events:
^ When a specific distance is exceeded
^ Recognition of damage or manipulation to the vehicle
^ "Circuit 15 ON" or "circuit 15 OFF" (ignition switched on or off)

The CAC forwards the location of the vehicle to the responsible command staff (e.g. police). The command staff can then decide whether to listen in or talk to the drive

Vehicle tracking can only be deactivated by the CAC.

If the multifunction antenna malfunctions (e.g. defective because of rollover), the emergency call system control unit automatically uses the emergency call system antenna (A2/52) to receive and transmit the initiation command or the "ATA alarm".