Compass Variance - Chevrolet 2005 Astro Owner's Manual

Compass Variance

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:
Setting the Variance
3-38
1. Find your location on the zone map. Record your
zone number.
2. Press and hold both the US/MET and the MODE
buttons while in the COMP/TEMP mode.
3. After five seconds, the compass will acknowledge
the variation mode by displaying the current zone
number. When it does, release both buttons.
4. Press US/MET until your zone number appears on
the display.
5. Press MODE to enter your zone number. Your
variance is now set and the display will return to
the COMP/TEMP mode.
Automatic Compass Calibration
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 US/MET and MODE 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.