Your vehicle may have an automatic dimming rearview mirror with a compass display. The mirror also contains OnStar® controls. For more information see OnStar® System .
The automatic dimming feature functions the same as that of the automatic dimming rearview mirror without a compass. See Automatic Dimming Rearview Mirror with OnStar® .
The mirror also includes an eight-point compass display in the upper right corner of the mirror face. When on, the compass automatically calibrates as the vehicle is driven.
Mirror Operation
(On/Off): Press and hold the button, located on the lower left side of the mirror face, for about three seconds to turn the automatic dimming feature on or off. The indicator light will illuminate when this feature is active. The automatic dimming feature is active each time the vehicle is started.Compass Operation
Press the on/off button once 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 compass heading.
Compass Calibration
If after two seconds, the display does not show a compass heading (for example, N for North), 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 reads a direction.
The compass can be placed in calibration mode manually by pressing and holding the on/off button until a C is shown in the compass display.
Compass Variance
The zone is set to zone eight upon leaving the factory. It will be necessary to adjust the compass to compensate for compass variance if you live outside zone eight. Under certain circumstances, as during a long distance cross-country trip, it will be necessary to adjust for compass variance. Compass variance is the difference between earth's magnetic north and true geographic north. If not adjusted to account for compass variance, your 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 the on/off button until a zone number appears in the display.
- Once the zone number appears in the display, press the on/off button quickly until the correct zone number appears in the display. Stop pressing the button and the mirror will return to normal operation. If C appears in the compass window, the compass may need calibration. See Compass Calibration listed previously.
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.
