Compass Module

The compass module operates by monitoring the vehicle position relative to the earth's magnetic north. The magnetic fields generated by the earth's north and south poles are divided into zones that differ from each other with respect to how the magnetic fields appear. Most geographic areas (zones) have a magnetic north compass point that varies slightly from the northerly direction on maps. The compass module utilizes a voltage supply circuit, ground circuit and a communication circuit to provide the compass heading data for display.

Factors within the vehicle can affect the ability of the compass module to accurately read the magnetic north. Calibrating the compass allows the compass module to compensate for these factors. Driving near power lines, or driving in the area of large iron or steel structures can temporarily change the compass heading. If the compass remains inaccurate after driving near such objects, calibrate the compass. Variations are generally 4 degrees between adjacent zones, and becomes noticeable as the vehicle crosses multiple zones. A correct zone setting eliminates the error.