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Position finding, function - GF82.95-P-3000CWU

MODEL 204.0 with CODE (359) TELE AID emergency call system 

Position finding function requirements 

IMPORTANT Depending on equipment installed one of the following control units is installed:

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:

The position finding function consists of the following subfunctions:

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:

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:

The wheel speed signals are recorded by the following RPM sensors:

The wheel speed signals from the RPM sensors are received by the emergency call system control unit in the following way:

The distance traveled data from the instrument cluster (A1) is received by the emergency call system control unit in the following way:

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.

IMPORTANTError 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 

IMPORTANT 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 

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:

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:

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:

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 driver.

IMPORTANT Vehicle tracking can only be deactivated by the CAC.

IMPORTANT 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".

REFER TO SYSTEM WIRING DIAGRAMS Electrical function diagram for TELEAID position finding With code (512) COMAND APS with DVD changer
With code (389) Mobile phone preinstallation with universal interface, USA/Canada Comfort telephony
PE82.95-P-2058-99FAA
  GPS antenna splitter, component description A2/5
With code (512) COMAND APS with DVD changer
GF82.62-P-3129CWU
  Telephone and GPS roof antenna component description A28/11 GF82.62-P-4119CW
  Frequency switchover control unit, component description N96
With code (389) Mobile phone preinstallation with universal interface, USA/Canada Comfort telephony
GF82.62-P-4204CWU
  Emergency call system control unit, component description N123/4 GF82.95-P-3212CWU 
  Emergency call system backup antennas component description A2/52 GF82.95-P-4002CWU