Hummer 2009 H2 - Manual (Page 211)

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. Or,
if the vehicle does not have DIC buttons, press and
hold the trip odometer reset stem for 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 strong magnetic field
interfering with the compass. Such interference may be
caused by a magnetic CB or cell phone antenna mount,
a magnetic emergency light, magnetic note pad holder,
or any other magnetic item. Turn off the vehicle, move the
magnetic item, then turn on the vehicle and calibrate the
compass.
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