Hummer 2006 H2 - Manual (Page 118)

Compass Calibration
The compass may need calibration if one of the
following occurs:
• If CAL is displayed while driving in the vehicle.
• After about five seconds, the display does not show
a compass heading (N for North, for example),
there may be a strong magnetic field interfering with
the compass. Such interference may be caused
by a magnetic antenna mount, a magnetic note pad
holder, or a similar magnetic item.
• The compass does not display the correct heading
and the compass zone variance is set correctly.
In order to calibrate, CAL must be displayed in the
mirror compass windows. If CAL is not displayed,
press and hold the on/off button for approximately
nine seconds or until CAL is displayed. Then release
the button. The compass is now in calibration mode.
The mirror can be calibrated in one of two ways:
• Drive the vehicle in circles at less than five mph
(8 km/h) until CAL is no longer displayed in the
comp/temp window.
• Drive the vehicle under normal operating conditions.
Compass Variance
Compass variance is the difference between earth’s
magnetic north and true geographic north. If not
adjusted to account for compass variance, the compass
could give false readings.
The mirror is set in zone eight upon leaving the factory.
It will be necessary to adjust the compass to
compensate for compass variance if the vehicle is
outside zone eight. Under certain circumstances, as
during a long distance cross-country trip, it will be
necessary to adjust for compass variance.
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