2008 Buick Lucerne Owner's Manual - Page 116

Automatic Dimming Rearview Mirror with Compass Your vehicle may have an automatic dimming rearview mirror with a compass. This feature enables the mirror to sense nighttime glare from vehicle headlamps from behind and automatically dim to reduce the glare to a safe level. The automatic dimming feature turns on 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 a few seconds. After a few seconds, the mirror will display the current compass direction. Compass Calibration If after a few seconds the display does not show a compass 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, note pad holder, or similar object. If the letter C or CAL appears in the compass window, the compass may need to be reset or calibrated. 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. O (On/Off): This is the on/off button. Automatic Dimming Mirror Operation The automatic dimming mirror function is turned on automatically each time the ignition is started. To operate the automatic dimming mirror, do the following: 1. Make sure the indicator light, located to the left of the on/off button, is on. If it's not, press and hold the on/off button until the light comes on, indicating that the mirror is in automatic dimming mode. 2. Turn off the automatic dimming mirror function by pressing and holding the on/off button until the indicator light turns off. 2-36