2003 GMC Yukon Owner's Manual - Page 136

To adjust for compass variance do the following: 1. Find your current location and variance zone number on the following zone map. 3. Keep pressing the on/off button until the desired zone number appears in the display. Release the button. After approximately four seconds of inactivity, the new zone number will be locked in and the comp/temp display will return. 4. Calibrate the compass as described below. Compass Calibration The compass may need calibration if one of the following occurs: • After approximately 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, 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. In order to calibrate, CAL must be displayed in the mirror compass windows. If CAL is not displayed, push the on/off button for approximately 12 seconds or until CAL is displayed. The compass can be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display reads a direction. 2. Press and hold the on/off button until a Z and a zone number appears in the display. The compass is now in zone mode. 2-42