The vehicle may have an automatic dimming rearview mirror with a compass. It may also have OnStar® controls. See OnStar® System for more information.
The mirror has an eight-point compass display in the upper right corner of 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.
Mirror Operation
MIRROR: Press this button to turn the automatic dimming feature on or off.(On/Off): For mirrors equipped with OnStar® controls, press and hold this button for several seconds to turn on the automatic dimming feature on or off.
The indicator light will come on when this feature is on. The automatic dimming feature will go on each time the vehicle is started.
Compass Operation
COMPASS: Press this button once to turn the compass on or off.(On/Off): For mirrors equipped with OnStar® controls, press this button to turn the compass on or off.
When the ignition and the compass feature are on, the compass will show two character boxes for about two seconds. After two seconds, the mirror will display the direction of the vehicle.
Compass Calibration
When on, the compass automatically calibrates as the vehicle is driven. If, after two seconds, the display does not show a compass direction, (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. If the letter C should ever appear in the compass window, the compass may need calibration.
The mirror can be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display shows a direction.
Mirrors equipped with OnStar® controls can be placed in calibration mode by pressing and holding the on/off button until a C is shown in the compass display.
Compass Variance
Compass variance is the difference between earth's magnetic north and true geographic north. 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. If not adjusted to account for compass variance, the compass could give false readings.
To adjust for compass variance, do the following:
- Find the current location and variance zone number on the following zone map.
- Press and hold COMPASS (or the on/off button for mirrors equipped with OnStar® controls) until a zone number appears in the display.
- Once a zone number appears in the display, press the COMPASS button (or the on/off button for mirrors equipped with OnStar® controls) quickly until the correct zone number appears in the display. If C appears in the compass window, the compass may need calibration. See "Compass Calibration" explained previously.
