White Square on Front of Mirror?

Greetings all,

I’m looking at mounting a dash cam. It will hang between the rear view mirror and the windshield. I notice there is a white square on the front of the mirror (the side that faces the glass). What is it? And what happens if the dash cam obstructs it?

Thanks in advance.

 

I think it is a light sensor.

 

Light sensor. The mirror may not dim correctly if it’s blocked.

 

I wouldn't put dashcam behind mirror since it will be hard to operate it and might interfere if you need to change mirror position. And that thing of course probably some sort of sensor. I put dashcam slightly under the mirror on passenger side right under dots on windshield.

 

It has something to do with dimming the rear view mirror. I covered mine as well as pointed a flashlight at it at night and it did weird things to the dimming on the rear view mirror.

I think if you put something in front of the sensor, it may not be so bad as long as you don't completely block light from entering the sensor.

 

The rearview mirror contains two sensors - one forward facing and one rearward facing - that work together to identify and eliminate dazzling light. The forward facing sensor detects ambient light, while the rearward facing sensor detects the light from vehicle headlights behind.

 

Yes, I got Safety Sense stuff all around the mirror, so at first I was sort of wondering of where to put camera. My old SR5 didn't have anything around mirror and putting dashcam was easy - i was almost at the center or windshield. With Safety Sense cameras I had to put dashcam a little more to the passenger side then I intended, but after all it worked out well.

 

Tell me more. I thought the one facing forward was the ambient sensor to turn the headlights on automagically when dusk hits. And the rear facing one makes almost no sense since the rear door and window sits higher than most any vehicle approaching from behind and the dark tint on the rear glass will block most offensive light reaching the rear-view mirror.

 

See if Blendmount has a solution for your camera.

 

Very cool, tons of dash cams out there, none of them will block the light sensor on the mirror enough to affect efficiency.

 

No I think that’s the little button shaped nub on the center of the dash.

 

It might be better to put the dash cam to the right of the safety sense stuff anyway. I did a “dry fit” behind the mirror and Scanny is right. It’s tight back there. Tough to get to the controls.

 

I mounted my Garmin mini dash cam high up on the driver side of the windshield behind the mirror for a higher viewing angle and so I wouldn’t be distracted by its red power LED. Then I noticed that the auto-dimming mirror function was always dim even in the daytime.

It’s because I obscured that forward facing photocell, so the mirror behaves as if it’s always in night mode and keeps the mirror dimmed.
I wound up removing the mount and re-positioning it so the photocell could see the light, and all is well now.

 

Depends on the camera, but its got to be a light sensor. Though even with my Blackvue semi obstructing it it works perfect since there is also a sensor for cars behind (which is more important).

My Blackvue is literally less than 1/4" above the sensor. Plus i have tons of other stuff around my mirror so not to obstruct any visibility. Definitely ideal having it in from of the RVM making it a bit stealthy and out of view.

 

From the Factory the Toyota rear window is not tinted so dark that it interferes with the rear facing sensor that detects bright headlights coming in from behind.

Then If your car has automatic headlights, it also has a headlight control sensor. Essentially, this is what’s responsible for turning your headlights on and off based on ambient light levels. The sensor is located on the dash near the windshield in front of the driver’s position. It monitors the amount of light outside through the windshield. When it detects dropping light levels, it turns the headlights on.

 

Lots of good info here, folks. Thanks!

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During the day, put you finger over the front sensor on the mirror. The mirror dims down. It must be on auto.

I couldn't tell the rear sensor did anything during the day by blocking it or shining a flashlight into it. Will try again after dark.

 

Good idea! Either that or duct tape!

 

Checked manual for my 2022 TRD Off-road - looks like it an Anti-glare function sensor.

Responding to the level of brightness of the headlights of vehicles
behind, the reflected light is automatically reduced.

 

I use painter's tape to dim LEDs. The number of layers you put on controls the brightness. And it comes off easy if need be.

 

I've been noticing my rear mirror hasn't been dimming properly at night lately. I bet its because I have my Garmin dashcam back there! I guess I'll attempt to move it an inch to the left or right and see if that improves anything.

 

Sorry to sidetrack the thread - would love to see a pic of your Garmin cam. I am also thinking of using a Garmin for a rear dash cam. I already have the Mini 2 up front. Thanks!

 

I put the auto dimmer on a switch because it is always on and the little green light bugged me - especially when I don't need it on. I added a pushbutton switch to control it so now it is always off and turns on only when I need it (someone behind me with highbeams on or headlights not angled properly). I had to trim some plastic to make it fit but really happy with the finish. It's located where an SOS button would be on other models.

 

Oh sorry, I meant "back there" as behind the mirror facing forward. I did have the same idea though, to get a second Garmin as a rear camera. If I ever mount one, I'll do my darndest to remember this thread send a photo.

 

The auto-dimming mirror on your 2015 doesn’t already have a power button? My 2018 does.

 

It does, but it is always on. I would rather have it always off and turn on when needed. I know it's kinda silly but I'm all about the little details.

 

I installed the Garmin Mini 2 Dash Cam and the Dongar adapter yesterday. It’s a little involved, but this install video is excellent:



I would add a couple of notes:

1. I chose to locate the USB port on the passenger side of the mirror pillar, between the pillar and the Safety Sense camera housing. It’s more hidden that way. It was a 15 minute job requiring only pry tools and a screwdriver.

2. When it’s time to place the camera, it’s best to have already downloaded the app onto your phone and have it set up and running, so you can see what the camera sees, on your phone, before you peel the film off the mount and stick it to your windshield. I first placed the camera close to the mirror pillar, but the when I looked at the image on the phone an obnoxiously large portion of the camera image was obscured by a blacked-out portion of the glass. I had to pry the mount off the glass and use the included second mount to relocate the camera.

3. I chose to locate the camera behind the mirror so it wouldn’t encroach into my field of view, and to avoid seeing the red LED that ElectroBoy mentioned above. I knew this might affect the dimming function of the mirror. I took the 4Runner for a test drive last night to test the dimming function, but there wasn’t much traffic so more testing may be necessary.

4. When installing the Dongar adapter I put a blanket over the windshield because the glare from outside made it hard to see. I noticed that when the mirror dims, it does so gradually.

As I’ve placed it, the camera sits too close to the mirror to operate the button on the back without moving the mirror. But the camera accepts voice commands and works pretty well.



The camera is invisible except for the pad of the adhesive mount at the upper left corner of the mirror.

 

Here’s a still image from the camera. I was able to take the picture with a voice command.