The auto-dimming function is an anti-glare capability which automatically reduces glare coming from headlights of vehicles behind you.
By pressing the power button, the autodimming function is toggled on or off.
When the auto-dimming function is on, the function indicator will illuminate in green. Even with the mirror in anti-glare mode, the mirror surface turns bright if the transmission is shifted into the “R” (reverse) position. This is to ensure good rearward visibility during reversing.
The mirror has a photosensor attached on both the front and back sides. During nighttime driving, these sensors detect distracting glare from vehicle headlights behind you and automatically dim the mirror to eliminate glare and preserve your vision. For this reason, use care not to cover the sensors with stickers, or other similar items. Periodically wipe the sensors clean using a piece of dry soft cotton cloth or an applicator.
NOTE
When cleaning the mirror, use a paper towel or similar item dampened with glass cleaner. Do not spray glass cleaner directly on the mirror surface. By doing so, the sprayed glass cleaner could enter the inside of the mirror housing. That may cause a malfunction in the mirror.