Auto dim mirror

[is200 Newbie]

Is it really noticeable when this function is working (this is for the interior mirror) - I can see the light on and it turns a smokey colour when being lit up not that much that I can say wow that's a good feature.

The sensor on the back of the mirror - between the mirror housing and the windscreen - what function does this have?

[Wisty]

Coming to auto dimming mirrors from a car that didn't have them, this was one of my favourite features.  I guess I kinda take it for granted now though.  You forget how horrible being dazzled by the turd in a Transit that's about 2ft from your rear bumper is.

[steveledzep]

As Chris says, you become accustomed to such things.  I also value the door mirrors dimming too.

 

The sensor you refer to Noobie may be the rain sensor on the windscreen, it's certainly in that area.

[Linas.P]

No... there is indeed the sensor on the mirror itself and not the rain sensor attached to windshield. I would speculate that it is ambient light sensor, so mirror can calculate whenever light coming is ambient, or it is actually other cars headlights dazzling you, otherwise your mirror dim itself all the time during the day.

[Linas.P]

quick google search and ... yeap I was right it is ambient light sensor:

 

[NemesisUK]

Yes, there is a light sensor behind the mirror glass and the one you refer to. When the car detects more light striking the mirror glass (must be from the headlamps of the car  behind as your car interior is always darker than outside) than detected from the front facing sensor it will dim the interior and exterior mirrors. The function cancels when selecting reverse gear.

[ahmedali44]

I had that on my 2006 is220d se-l but not on my 2009 se-i. I think only comes on se-l spec. 

Mine got different system now u got to push mirror to go dark but no sensor unlike my ex is220d, it had a small sensor in it. mirror was lot bigger too. was good idea though 

 

[Linas.P]

That is funny, I though auto dimming mirrors were standard on all IS... that is real shame, it shows how we take it for granted these days, I can hardly remember having nob to dim the mirror.. probably last car I had with "manual dimming" was 1992 Mazda MX3 (when I was 16), even 1988 BMW 525i had auto dimming mirror (not sure if from factor or retrofitted thought).

[NemesisUK]

There is a disable button on the bottom of the mirror, from my owner's handbook (no idea if it's the same across the range)

 

"Changing automatic anti-glare function
mode
ON/OFF
When the automatic anti-glare function
is in ON mode, the indicator illuminates.
The function will set to ON mode each
time the power switch is turned to ON
mode.
Pressing the button turns the function to
OFF mode. (The indicator also turns
off.)"

[Linas.P]

I wonder.. why would anyone want to turn it off?

[is200 Newbie]

It was the rear mirror sensor I could not work out as the glare comes from the rear of the car onto the mirror glass - why would the sensor be on a spot that does not sense the glare.

Well explained with the video Linas

[ahmedali44]

inside car mirror goes black but no sensor also side mirrors go black too just came from a 500 miles trip 

[steveledzep]

[NemesisUK]

Sounds like the old fashioned manual mirrors that 'dipped' literally by tilting slightly, going dark as the reflecting surface looked downward. Slightly updated by incorporating liquid crystal and electronics to dip both mirrors when driver touches the button on the mirror?

[ahmedali44]

Na didn't tilt inside mirror to go black 

[NemesisUK]

Na, just touched the button