Buick 2002 Park Avenue - Manual (Page 115)

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Compass Calibration
If, after two seconds, the display does not show a
compass heading (N for North, for example), there may
be a strong magnetic field interfering with the compass.
Such interference may be caused by a magnetic antenna
mount, magnetic note pad holder or a similar magnetic
item. If the letter C should ever appear in the compass
window, the compass may need calibration.
The mirror can be calibrated by driving the vehicle in
circles at 5 mph (8 km/h) or less until the display reads
a direction.
Mirrors equipped with OnStar controls can be placed in
calibration mode by pressing and holding the on/off
button until a C is shown in the compass display.
Compass Variance
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. Compass variance is the difference
between earth’s magnetic north and true geographic
north. 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. Press and hold COMPASS (or the on/off button for
mirrors equipped with OnStar controls) until a zone
number appears in the display.