1998 Oldsmobile Aurora Owner's Manual - Page 116

If, after two seconds, the display does not show a compass heading ( " N ' for North, for example),there may be a strong magnetic field interfering with the compass. Such interference may be caused by a magnetic antenna mount, magnetic note pad holder or a similar magnetic item. Compass Variance The mirror is set in zone eightupon leaving the factory. It will be necessary to adjustthe compass to compensate for compass variance if you live outside zone eight. Under certain circumstances, as during a long distance cross-country trip, it will be necessary to adjust for compass variance. Compass variance is the difference between earth's magnetic north and true geographic north. If not adjusted to account forcompass variance, your compass could give false readings. To adjust for compass variance: 1. Use the COMPASS button located at the bottom of the mirror. 2. Press and hold the COMPASS button until a zone number appears in the display. 3. Find your current location and variance zone number on the following zone map. 4. Press the COMPASS button on the bottom of the mirror until the new zone number appears in the display. After you stop pressing the button, the compass will need to be calibrated. (This is the automatic calibration mode. Drive in a circle to calibrate the mirror. See "Compass Calibration" following.) 2-50