Compass Variance - Buick 2004 Park Avenue Owner's Manual

Compass Variance

Compass variance is the difference between earth's
magnetic north and true geographic north. 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 you live outside zone eight.
Under certain circumstances, as during a long distance
cross-country trip, it will be necessary to adjust for
compass variance. If not adjusted to account for
compass variance, your compass could give false
readings.
To adjust for compass variance, do the following:
1. Find your current location and variance zone
number on the following zone map.
2-38
2. Press and hold COMPASS (or the on/off button for
mirrors equipped with OnStar
zone number appears in the display.
3. Once a zone number appears in the display, press
the COMPASS button (or the on/off button for
mirrors equipped with OnStar
the correct zone number appears in the display.
Stop pressing the button and the mirror will return
to normal operation. If C appears in the compass
window, the compass may need calibration.
See "Compass Calibration" explained previously.
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