Your vehicle may have an automatic dimming rearview mirror with OnStar® and a compass display. For more information, see OnStar® System . For more information on Intellibeam™, see "Intellibeam Intelligent High-Beam Headlamp Control System" under Exterior Lamps .

The mirror 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.

Your vehicle is equipped with an automatic dimming rearview mirror. The automatic dimming feature is activated whenever the vehicle is turned on and dims only during nighttime driving.

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.

If after two seconds the display does not show the correct 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.

The compass can be placed in calibration mode manually by pressing and holding the "auto highbeam" button for approximately nine seconds until a C is shown in the compass display.

The mirror can then be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display reads a direction.

The mirror is set to zone eight upon leaving the factory. It will be necessary to adjust the compass to compensate for compass variance if the vehicle is driven outside zone eight. Under certain circumstances, such as a long distance, cross-country trip, it will be necessary to adjust the compass variance.

Compass variance is the difference between earth's magnetic north and true geographic north. If the mirror is not adjusted to account for zone changes, the compass could give false readings.

To adjust for zone changes, do the following:

1. Find your current location and variance zone number on the zone map that follows.



2. Press and hold the "auto highbeam" button approximately six seconds until a zone number appears in the display.
3. Once the zone number appears in the display, press the "auto highbeam" button quickly until you reach the correct zone number. Stop pressing the button and the mirror will return to normal operation. If C appears in the compass window, the compass needs calibration. See "Compass Calibration" listed previously.

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.