Chevrolet 2007 Avalanche Owner's Manual page 151

To adjust for compass variance:
1. Find your current location and variance zone
number on the following zone map.
2. Press and hold the COMP button for
five seconds until a zone number
appears in the display.
3. Press the COMP button on the bottom of the
mirror until the new zone number appears in
the display. After you stop pressing the
button, the display will show a compass
direction within a few seconds.
Cleaning the Mirror
Use a paper towel or similar material dampened
with glass cleaner. Do not spray glass cleaner
directly on the mirror as that may cause the liquid
cleaner to enter the mirror housing.
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