2004 Cadillac CTS-V Owner's Manual - Page 107

Compass Operation Press the on/off button once to turn the compass on or off. When the ignition and the compass feature are on, the compass will show two character boxes for approximately two seconds. After two seconds, the mirror will display the current compass heading. The mirror can be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display reads a direction. The compass can be placed in calibration mode by pressing and holding the on/off button until a C is shown in the compass display. Compass Variance Compass variance is the difference between earth's magnetic north and true geographic north. If the mirror is not adjusted for compass variance, your compass could give false readings. The mirror is set in zone eight upon leaving the factory. It will be necessary to adjust the compass to compensate for compass variance if you live outside zone eight. Under certain circumstances, such as a long distance, cross-country trip, it will be necessary to adjust the compass variance. Compass Calibration 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, note pad holder or similar object. If the letter C should ever appear in the compass window, the compass may need calibration. 2-41