Buick 2010 Lucerne - Manual (Page 142)

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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