If the vehicle has this feature, an automatic dimming mirror automatically dims to the proper level to minimize glare at night from lights behind your vehicle. For more information about OnStar®, see OnStar® System .
The mirror also includes a dual display in the upper right corner of the mirror face. The compass reading and the outside temperature will both appear in the display at the same time.
(On/Off): This is the on/off button.Automatic Dimming Mirror Operation
The automatic dimming mirror function is turned on each time the ignition is started. A light near the on/off button will come on to indicate the automatic dimming is on.
Press the on/off button for about four seconds to manually turn the automatic dimming function on or off.
Temperature and Compass Display
Press the on/off button, located to the far left, to cycle between °F, °C and off.
If the display reads CAL, the compass needs to be calibrated. For more information, see "Compass Calibration" later in this section.
If an abnormal temperature reading is displayed for an extended period of time, please consult your dealer. Under certain circumstances, especially in idle, an increase and delay in updating the temperature is normal.
Compass Variance
Press the on/off button twice to turn on the compass.
Compass variance is the difference between earth's magnetic north and true geographic north. If not adjusted to account for compass variance, the mirror's 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 of zone eight. Under certain circumstances, as during a long distance cross-country trip, it will also be necessary to adjust for compass variance.
To adjust for compass variance do the following:
- Find your current location and variance zone number on the following zone map.
- Press the on/off button approximately seven seconds until the word ZONE appears in the display. The compass is now in zone mode.
- Press and release the on/off button until the desired zone number appears in the display. After approximately four seconds of inactivity, the new zone number will be locked in and the compass/temperature display will return.
- Calibrate the compass as described below.
Compass Calibration
The compass may need calibration if one of the following occurs:
| • | After approximately five 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. |
| • | The compass does not display the correct heading and the compass zone variance is set correctly. |
In order to calibrate, CAL must be displayed in the mirror compass windows. If CAL is not displayed, push the on/off button for approximately 12 seconds or until CAL is displayed.
The compass can be calibrated by driving the vehicle in circles at 5 mph (8 km/h) or less until the display reads a direction.
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.
