Manual Dimming Mirror
WARNING
  Do not adjust the mirrors when your vehicle is moving. This could result in the loss of control of your vehicle, serious personal injury or death.

Pull the tab below the mirror toward you to reduce the effect of bright light from behind.
Automatic Dimming Mirror
WARNING
  Do not adjust the mirrors when your vehicle is moving. This could result in the loss of control of your vehicle, serious personal injury or death.

The mirror dims to reduce the effect of bright light from behind. It returns to normal when the bright light from behind is no longer present or if you shift into reverse (R).
Do not block the sensors on the front and back of the mirror.
Note:  A rear center passenger or raised rear center head restraint could prevent light from reaching the sensor.