1996 GMC Jimmy Owner's Manual - Page 109

Variance is the difference between magnetic norm and geographic north. In some areas, the difference between the two can be great enough to cause false compass readings. If this happens, follow these instructions to set the variance for your particular location: 1. Find your location on the zone map. Note your zone number. 2 . Press and hold both the ON/OFF and the USNET switches. The display will go off. 3. After five seconds, VAR CAL will appear on the display. When it does, release both buttons. 4. Press US/MET until your zone number appears on the display. 5. Press ON/OFF to enter your zone number. Your variance is now set. 2-52