GMC Sierra Denali 2500HD 2014 Owner's Manual page 106

GMC Sierra Denali 2500HD and 3500HD (GMNA-Localizing-U.S./Canada-
7142957) - 2014 - CRC 1st Edition - 3/28/13
5-6 Instruments and Controls
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
CHANGE COMPASS ZONE
displays. Or, if the vehicle does
not have DIC buttons, press the
trip odometer reset stem until
CHANGE COMPASS ZONE
displays.
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
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. Or, if the
vehicle does not have DIC
buttons, press and hold the trip
odometer reset stem for
Black plate (6,1)
two seconds to select the next
available variance zone. Repeat
this step until the appropriate
variance zone is displayed.
5. If calibration is necessary,
calibrate the compass. See
Compass Calibration
Procedure following.
Compass Calibration
The compass can be manually
calibrated. Only calibrate the
compass in a magnetically clean
and safe location, such as an open
parking lot, where driving the
vehicle in circles is not a danger.
It is suggested to calibrate away
from tall buildings, utility wires,
manhole covers, or other industrial
structures, if possible.
If CAL should ever appear in the
DIC display, the compass should be
calibrated.
If the DIC display does not show a
heading, for example, N for North,
or the heading does not change
after making turns, there may be a