Cadillac 2010 Escalade ESV Owner's Manual page 240

Compass variance is the difference between the earth's
magnetic north and true geographic north. If the
compass is not set to the zone where you live, the
compass may give false readings. The compass must
be set to the variance zone in which the vehicle is
traveling.
To adjust for compass variance, use the following
procedure:
Compass Variance (Zone) Procedure
1. Do not set the compass zone when the vehicle is
moving. Only set it when the vehicle is in P (Park).
Press the vehicle information button until
PRESS TO CHANGE COMPASS ZONE
displays.
4-48
2. Find the vehicle's current location and variance
zone number on the map.
Zones 1 through 15 are available.
3. Press the set/reset button to scroll through and
select the appropriate variance zone.
4. Press the trip/fuel button until the vehicle heading,
for example, N for North, is displayed in the DIC.
5. If calibration is necessary, calibrate the compass.
See Compass Calibration Procedure following.
I n f o r ma t i o n P r o v i d e d b y :