Buick 2006 Lucerne - Manual (Page 111)

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 the vehicle is 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, the compass could give
false readings.
To adjust for compass variance, do the following:
1. Find the current location and variance zone number
on the following zone map.
2. Press and hold the COMPASS button (or the on/off
button for mirrors equipped with OnStar ® controls)
until a 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
® controls) quickly until
the correct zone number appears in the display. If
C appears in the compass window, the compass
may need calibration. See “Compass Calibration”
explained previously.
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2006 - Buick Lucerne Owner Manual