Buick 2009 Lucerne - Manual (Page 119)

Compass Variance
The compass is set to zone eight. If you do not live in
zone eight or drive out of the area, the compass
variance needs to be changed to the appropriate zone.
To adjust for compass variance:
1. Find your current location and variance zone
number on the following zone map.
2. Press and hold O until the zone number displays.
The number shown is the current zone number.
3. Once the zone number displays, press O
repeatedly until the correct zone number displays.
Stop pressing the button and the mirror returns
to normal operation. If CAL appears in the
compass window, the compass may need
calibration. See “Compass Calibration” listed
previously.
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