GMC 2007 Sierra - Manual (Page 179)

Compass Calibration
The compass may need calibration if one of the
following occurs:
• After approximately 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, 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,
push the on/off button for approximately
12 seconds or until CAL is displayed.
The compass can be calibrated by driving the
vehicle in circles at 5 mph (8 km/h) or less until the
display reads a direction.
Passenger Airbag Indicator
The vehicle may be equipped with a passenger
airbag indicator, on the mirror glass, just above the
buttons. If the vehicle has this feature, the
mirror will display the word ON, or an airbag
symbol in Canada, when the passenger airbag is
enabled. For more information, see Passenger
Sensing System on page 103.
Cleaning the Mirror
When cleaning the mirror, use a paper towel or
similar material dampened with glass cleaner.
Do not spray glass cleaner directly on the mirror
as that may cause the liquid cleaner to enter
the mirror housing.
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