Your vehicle may have an automatic dimming rearview mirror with a compass. Your vehicle's mirror may also contain OnStar® controls. See OnStar® System for more information.
The mirror also includes an eight-point compass display in the upper right corner of the mirror face.
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 on the automatic dimming feature. Press it again to turn off the automatic dimming feature.(On/Off): For mirrors equipped with OnStar® controls, press and hold this button for several seconds to turn on the automatic dimming feature. Press and hold it again to turn the automatic dimming feature off.
The green indicator light will come on when this feature is active. The automatic dimming feature will be active 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 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 approximately two seconds. After two seconds, the mirror will display the compass heading.
Compass Calibration
When on, the compass automatically calibrates as the vehicle is driven. If, after two 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. 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.
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 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. If not adjusted to account for compass variance, your compass could give false readings.
To adjust for compass variance, do the following:
- Find your 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. 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" explained previously.
