Compass Variance
Compass variance is the difference between earth’s
magnetic north and true geographic north. If the mirror
is not adjusted for compass variance, the compass
could give false readings.
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
driven outside zone eight. Under certain circumstances,
such as a long distance, cross-country trip, it will be
necessary to adjust the compass variance.
To adjust for compass variance, do the following:
1. Find your current location and variance zone
number on the zone map that follows.
2. Press and hold the compass button until a zone
number appears on the display.
3. Once the zone number appears on the display,
press the compass button quickly until you reach
the correct zone number. If C appears in the
compass window, the compass may need
calibration. See “Compass Calibration” listed
previously.
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Automatic Dimming Rearview
Mirror with OnStar
®, Compass
and Temperature Display
Your vehicle may have an automatic dimming rearview
mirror with OnStar®, compass and temperature
display. If the vehicle has this feature, the automatic
dimming mirror automatically dims to the proper level to
minimize glare at night from lights behind your vehicle.
The mirror also has a dual display in the upper right
corner of the mirror that shows the compass reading and
the outside temperature.
There are three additional buttons for the OnStar
®
system. See your dealer for more information on the
system and how to subscribe to OnStar®. See OnStar®
in the Index for more information.
YOn/Off:Press this button to operate the automatic
dimming, compass and temperature features.
Automatic Dimming Mirror Operation
The automatic dimming mirror function is turned on each
time the ignition is started. A light near the on/off button
will come on to indicate the automatic dimming is on.
If the automatic dimming function is off, press and hold
the on/off button for four seconds to manually turn
the system back on.
Temperature and Compass Display
Press the on/off button, located in the center, to cycle
between °F, °C and off. If the display reads CAL,
the compass needs to be calibrated. For more
information, see “Compass Calibration” later in this
section.
If an abnormal temperature reading is displayed for an
extended period of time, please consult your dealer.
Under certain circumstances, a delay in updating
the temperature is normal.
Compass Variance
Compass variance is the difference between earth’s
magnetic north and true geographic north. If not
adjusted to account for compass variance, the mirror’s
compass could give false readings. 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.
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