The receiver of the GPS satellite navigation system supplies the navigation computer with the current position of the vehicles in degrees latitude and longitude.
A CD with map data is loaded in the CD drive of the navigation computer. The navigation computer combines the vehicle position calculated by the GPS with this map data.
The current position is shown on the on-board monitor under "location display".
The driver can enter a destination. The navigation computer calculates a route from the current location to this destination based on selectable criteria (main trunk roads, shortest distance, etc.). The calculated route is shown in the route display.
With the aid of arrow indicators and distance data on the on-board monitor as well as an enunciator function, the navigation computer indicates how and where to get into the correct lane or turn off while driving.
The navigation computer calculates the distance covered from the signals of an ABS wheel speed sensor.
The gyro informs the navigation computer of the rotary movements of the vehicle (e.g. when turning off etc.). The gyro is installed in the casing of the navigation computer.
The magnetic field sensor known from the navigation system 1 is no longer required and is replaced by the gyro.
An alternative route is recalculated automatically if the driver does not follow the turn-off instructions.
A CD drive is integrated in the navigation computer. The map CD is loaded in this drive.
The navigation computer also features a fan. If the cooling capacity of the fan is not sufficient, the navigation computer is switched off due to overheating and this status is indicated on the on-board monitor.
The gyro is designed as an inertia sensor which records the forces which occur during a change in direction and transfers this data to the navigation computer in the form of a voltage change. This gyro is accommodated in the casing of the navigation computer.
The G lobal P ositioning S ystem is a system which was originally developed for military use, in which approx. 20 satellites in earth's orbit send position-related signals. These signals are evaluated by a computer specially developed for this purpose and converted into a position. The accuracy of the system varies, however, it is at least within 100 m.
GPS reception is only possible when unobstructed view of the sky is ensured.
The GPS in conjunction with the BMW navigation system consists of an aerial and a receiver which evaluates the satellite data received via the aerial and transfers the calculated vehicle position to the navigation computer.
In the navigation system, a symbol representing GPS reception is indicated in the top right corner of the map display.
The number of white dots in the symbol corresponds to the number of satellites from which signals are being received.
When a satellite symbol and the letters "GPS" appear in the display, this indicates that the quality of the received satellite signals is sufficient to calculate the current vehicle position.
The navigation computer evaluates the signals from an ABS speed sensor (E38 and E39 series: front left wheel, E46: rear left wheel) and then determines the distance covered.
The data which the navigation computer requires for route planning are stored on the map CD. It is advisable to use the relevant updated version in order to cater for any changes in the road system.
The navigation system can only be selected when a road map CD is inserted in the drive.
The sound signals are transferred via 2 AF lines either to the video module or - if no video module is installed (refer to explanation of system setup at the end of this description) - directly to the radio.
The picture signals are transferred via RGB lines either to the video module or - if no video module is installed (refer to explanation of system setup at the end of this description) - directly to the LC monitor.
It should be noted that different pins are assigned when the picture signals are transmitted directly to the LC monitor or first to the video module.
The user interface, i.e. the menus on the on-board monitor is set up by the navigation computer.
The troubleshooting procedure is described in the document "Troubleshooting in the navigation system 2".
See <Navigation system> <Documents> < troubleshooting in navigation system 2>
Important!
There is no diagnostic program for the navigation system 2.
In contrast to the navigation system of the 1st generation, a complex calibration driving procedure is not necessary.
Important!
After replacing the navigation computer, a test drive lasting approx. 15 minutes is necessary, during which GPS reception must be ensured. For details refer to the document "Troubleshooting in navigation system 2".
If a new version of the operating software is offered by BMW, it should be loaded as follows (also refer to instructions on the CD):
Important!
Do not change the terminal setting during the loading procedure! Ensure adequate voltage rating in the vehicle electrical system.
If the vehicle also has provisions for a TV, in the same way as in the 1st generation, the on-board monitor system consists of:
The navigation system is connected to the I-bus and linked via RGB and AF lines to the video module 2 which in turn is an I-bus user.
In contrast to earlier versions, the graphics stage, i.e. the instrument to build up the graphics on the on-board monitor (e.g. menus) is now integrated in the navigation computer.
The sound for the navigation instructions is switched through from the video module to the radio.
Without the TV option, the on-board monitor system consists of the following components:
It should be noted that this complete system does NOT feature a video module.
The graphics for menus etc. are created in the navigation computer.
In this setup, the picture signals are transmitted from the navigation computer via RGB lines directly to the LC monitor.
Sound information is transmitted via AF lines to the radio.