How to tell if your side mirrors are auto dimming

I recently purchased a used 2009 M3. I noticed that right mirror has some sort of blue film and maybe the film has become old and there's some sort of double vision in the mirror.

So I'm trying to replace the mirror with ULO mirror from ebay. This particular mirror I'm looking at on ebay says it's not compatible with auto dimming mirrors.

How do I tell if my side mirrors are auto dimming?

The easiest would be to check your vin with a bmw vin check website.
It tells you all your car has from factory.

I believe another way is to look at the bottom of the rear view mirror and you will see spot the size of a pencil eraser on the glass. That is the spot that picks up the shining lights and dims all 3 mirrors. If you don't have that then you don't have that feature. That's how it was on my previous 3 series. Maybe its different in the M cars?

Drive in the dark. They turn blue if they are auto dimming.

Look at them

When they dim, there is a border around them. If there is not a border of different contrast, they’re not dimming.

Also if you’re fricking blinded by the light, they’re not dimming. 😂

Even in the day if you look around the edges of the mirror you can see the seam

Shine the flashlight on your phone in the rearview mirror

Thank you. I figured out that I do I have auto dimming mirrors. It has a blue tint except around the border of the mirror. It looks like whatever material makes it dim has run down from the top of the mirror to the bottom and needs to be replaced.

Mr. BMW wrote

I believe another way is to look at the bottom of the rear view mirror and you will see spot the size of a pencil eraser on the glass. That is the spot that picks up the shining lights and dims all 3 mirrors. If you don't have that then you don't have that feature. That's how it was on my previous 3 series. Maybe its different in the M cars?

Same deal in the M.

serranot wrote

When they dim, there is a border around them. If there is not a border of different contrast, they’re not dimming.

Also if you’re fricking blinded by the light, they’re not dimming. 😂

This!

Had no idea my car dimmed the side mirrors until I noticed the undimmed border around them. You'd notice right away if they're dimming.

I didn't want to start a new thread since I'm still talking about the same thing but... to replace this auto dimming mirror, do I just pry the glass off from the mirror side? Does anyone have any tips for me? Thanks.

vroomM3 wrote

I didn't want to start a new thread since I'm still talking about the same thing but... to replace this auto dimming mirror, do I just pry the glass off from the mirror side? Does anyone have any tips for me? Thanks.

http://www.m3post.com/forums/showthread.php?t=316193

Mvy wrote

Drive in the dark. They turn blue if they are auto dimming.

Hmmmm....they say if we are wise we can learn something new everyday...
I always figured the mirrors were too cold when they were turning blue...

loveskiing wrote

Hmmmm....they say if we are wise we can learn something new everyday...
I always figured the mirrors were too cold when they were turning blue...

Or they were just being teased by a female mirror

EJT86 wrote

Or they were just being teased by a female mirror

Right thought but that would be more evident in the ball joints