System Description: Overview
The electrical compass shows the azimuth information in the 8-directions (N, NE, E, SE, S, SW, W, NW) to the audio-HVAC display unit via the audio unit
The ignition switch must be in the ON (II) position for the electrical compass unit to communicate with the audio unit and to do a self-test
The self-test function checks for the voltage, non-volatile memory (NVM), and ROM status in the electrical compass unit
The electrical compass unit has a self-calibration function It detects and compensates for magnetic anomalies caused by bridges, subways and large steel structures When the vehicle leaves an area with strong magnetic interference field (2400 mG or more), the electrical compass unit automatically begins calibrating If needed, you can calibrate the compass (see ELECTRICAL COMPASS ZONE SELECTION AND CALIBRATION )
Zone selection is required to compensate for the difference between magnetic North and geographic North This deviation is referred to as declination, the compass compensates for decimation when you select the zone where the vehicle is located (see ELECTRICAL COMPASS ZONE SELECTION AND CALIBRATION )