2006 GMC Yukon Owner's Manual - Page 135

To adjust for compass variance, do the following: 1. Find your current location and variance zone number on the map. 3. Scroll through the zone numbers that appear in the compass/temperature window on the mirror by pressing the on/off button. Once you find your zone number, release the button. After about four seconds, the mirror will return to the compass display, and the new zone number will be set. Automatic Dimming Rearview Mirror with OnStar®, Compass and Temperature Display Your vehicle may have this feature. When on, the automatic dimming mirror dims to the proper level to minimize glare from lights behind you after dark. The mirror has a dual display in the upper right corner of the mirror face that shows the compass reading and the outside temperature. Control buttons for the OnStar® system are at the bottom of the mirror. See OnStar® System on page 2-50 for more information about the services OnStar® provides. 2. Press and hold the on/off button for six seconds. Release the button when ZONE is displayed. The number shown is the current zone number. P (On/Off): This is the on/off button. 2-39