The vehicle may have an automatic dimming rearview mirror with OnStar®, a compass and map lamps. Three OnStar® buttons are at the bottom of the mirror. See OnStar® System for more information on the services OnStar® provides.
Mirror Operation
The mirror automatically changes to reduce glare from headlamps behind you. A time delay feature prevents rapid changing from the day to night positions while driving under lights and through traffic.
(On/Off): The automatic dimming feature is activated when the vehicle is started. The automatic dimming feature is turned on or off by pressing this button located on the lower part of the mirror. Press and hold the button for up to three seconds to turn this feature on or off.(Indicator Light): This light will turn on when the automatic dimming feature is active.
Map Lamps
The mirror has map lamps located at the bottom of the mirror. To manually turn the lamps on or off, press the button next to each lamp.
Compass Operation
The mirror has an eight-point compass display in the bottom of the mirror face.
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 current compass heading. For example, NE is displayed for north-east.
Compass Calibration
If after two seconds the display does not show a compass heading, there may be a strong magnetic field interfering with the compass. Such interference may be caused by a magnetic antenna mount, note pad holder or similar object. If the letter C appears in the compass window, the compass needs calibration.
The mirror compass 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 by pressing and holding the left map light button until a C appears on the compass display.
Compass Variance
Compass variance is the difference between earth's magnetic north and true geographic north. If the mirror is not adjusted for compass variance, your compass could give false readings.
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, such as a long distance, cross-country trip, it will be necessary to adjust the compass variance.
To adjust for compass variance, do the following:
- Find your current location and variance zone number on the zone map that follows.
- Press and hold the on/off button until a Z and a zone number appears on the display. The compass is now in zone mode.
- Once the zone number appears on the display, press the on/off 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 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.
