Ford 2009 Expedition Owner's Manual page 116

Driver Controls
Automatic dimming interior rear view mirror
Your vehicle is equipped with an interior rear view mirror which has an
auto-dimming function. The electronic day/night mirror will change from
the normal (high reflective) state to the non-glare (darkened) state
when bright lights (glare) reach the mirror. When the mirror detects
bright light from behind the vehicle, it will automatically adjust (darken)
to minimize glare.
Without microphone
With microphone
The mirror will automatically return to the normal state whenever the
vehicle is placed in R (Reverse) to ensure a bright clear view when
backing up.
Do not block the sensors on the front and back of the interior
rear view mirror since this may impair proper mirror
performance.
Do not clean the housing or glass of any mirror with harsh
abrasives, fuel or other petroleum-based cleaning products.
Note: If your vehicle is equipped with a reverse camera system, a video
image will display in the mirror or the navigation system display (if
equipped) when the vehicle is put in R (Reverse). Refer to Reverse
camera system in the Driving chapter.
116
2009 Expedition (exd)
Owners Guide, 1st Printing
USA (fus)