2005 Hummer H2 Owner's Manual - Page 118

Compass Operation Press the COMP button briefly to turn the compass on or off. When the ignition and the compass feature are on, the compass will show two character boxes for about two seconds. After two seconds, the mirror will display the compass heading. In order to calibrate, CAL must be displayed in the mirror compass windows. If CAL is not displayed, push the COMP button for about eight seconds or until CAL is displayed. The compass can be calibrated by driving the vehicle in circles at five mph (8 km/h) or less until a direction is displayed. Compass Calibration The compass may need calibration if one of the following occurs: Compass Variance Compass variance is the difference between earth's magnetic north and true geographic north. If not adjusted to account for compass variance, the 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 the vehicle is outside zone eight. Under certain circumstances, as during a long distance cross-country trip, it will be necessary to adjust for compass variance. • If CAL is displayed while driving in the vehicle. • After about five 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, a magnetic note pad holder, or a similar magnetic item. • The compass does not display the correct heading and the compass zone variance is set correctly. 2-42