Adjustment of magnetic field zones and calibration
The worldwide magnetic field zones are permanently stored in the interior mirror. The magnetic field zones represent the deviations in relation to an ideal magnetic field for earth. The orientation "North" is precisely determined by the magnetic field zones.
The current magnetic field zone may be adjusted according to the geographic location. For example, Germany is located in magnetic field zone "8".
A vehicle has its own magnetic field. This makes it possible for the magnetic field sensor to measure an overlapping of the magnetic field with the earth's magnetic field. This overlapping is "worked out" by calibrating the compass.
A changed magnetic field is normally calibrated "automatically".
The vehicle's magnetic field may change under the following special circumstances:
- Powerful vibration during an accident
- Very large external magnetic field - e.g. if a vehicle passes under a train when travelling through an underpass
However, a manual calibration may speed up the automatic calibration.
from 09/2006: Further adjustments
Different time-based adjustment menus can be obtained by means of the adjustment button:
- 0 to 3 seconds: Display ON/OFF
- 3 to 6 seconds: Adjustment of magnetic field zones (0 -15)
- 6 to 9 seconds: Calibration (C)
- 9 to 12 seconds: Left-hand drive or right-hand drive (L or R)
- 12 to 15 seconds: English or German (E or O)
Release the adjustment button when the correct menu is obtained. Select values in the menu by pressing briefly. After approx. 5 seconds the value is stored and the menu is automatically exited.
up to 09/2006: Fault display
The LC matrix for the LCD display lights up completely if a system fault develops. A fault is displayed under the following conditions:
- If the vehicle is highly magnetized (2, 200-2, 500 milligauss), the measuring range of the magnetic field sensor will be exceeded.
- If a fault develops in the circuitry of the magnetic field sensor.
Gauss is the unit of measurement for magnetic flux density.