GMC 2000 Envoy Owner's Manual page 109

COMP/TEMP: The display provides the outside
temperature and one of eight compass readings to
indicate the direction the vehicle is facing.
Before you turn on the ignition and move the vehicle,
the temperature indicated will be the last outside
temperature recorded with the ignition on. If the
outside temperature is 37 _ F (3 _ C) or lower, the
display will toggle between the word ICE and the
current temperature every eight seconds. This is a
warning to the driver that road conditions may be icy,
and that appropriate precautions should be taken.
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The compass is self calibrating, so it does not need
to be manually set. However, if C (Calibration) is
displayed, the compass will need to be calibrated.
You may also place the compass in a noncalibrated
mode by pressing and holding the MODE and US/MET
buttons simultaneously while in the COMP/TEMP
mode. After about 10 seconds, the compass will display
C and you can release the buttons. Drive the vehicle in
a complete 360 _ circle three times at a speed of less
than 5 mph (8 km/h), and the compass will function
normally. Once the calibration is complete, the display
will return to a compass reading.
Variance is the difference between magnetic north and
geographic north. In some areas, the difference between
the two can be great enough to cause false compass
readings. If this happens, follow these instructions to
set the variance for your particular location:
1. Find your location on the zone map earlier in this
section. Note your zone number.
2. Press and hold both the MODE and the US/MET
buttons in the COMP/TEMP mode.
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