Auto Dim Mirror Sensor blocked/shadowed

Some folks have turned the mirror upside down to solve the problem.

 

It would still be easy to see. Perhaps not as easy to use...

Tom

 

I used two small right-angle prisms. Inelegant, but functional.

 

This is a 2010 Prius forum. On the 2010 Prius it is impossible to turn the mirror upside down.

I might disassemble the mirror and move the sensor.

 

I had my mirror off today. I tried some guitar picks to try to pry open the case but I didn't want to force it too much prior to doing some more research.

I had a similar thought as you for relocating the sensor.

My thought would be to disable the on-board sensor and wire an external duplicate sensor at the half-way point on the right side of the mirror. If I couldn't dig up a duplicate sensor I would just unsolder the one on the board and relocate. A small hole could be drilled in the case or come out through the wiring harness hole.

Does anyone know if they are using a photo-diode or CdS for the sensor?

 

I sent Toyota a note on the mirror and the pax side rattle.

 

I can confirm that the mirror uses phototransistors. These are faster to respond than the older CdS sensors.

Here are some pics. The rear-facing one has some shielding around so I decided not to move it. The device has 4 pins. The die sits on one and there are bond wires going to the die from the other 3.

 

Wow those are great pictures. I like the one of the bond wires. You must have a great camera.

 

Thanks, just a 5 year old point and shoot. Canon A620 - it has very good macro capability. The bond wire shot was taken with a loupe on front of the lens.

Oh yah, Aperture priority (smallest aperture) and lots of light.

 

Had the mirror moved
By having another holder( button what ever you want to call them) put right above the existing holder that's cemented to the glass .
It raises the mirror just high enough to help with the dimming issue
it works and its an easy fix
By the way Toyota has had many complaints about the position of the mirror and the dimming issue
2006 was my first letter out to them on this .Same answer no none problem report blah blah blah .
This was easier .

 

sorry almost a double post

 

Has anyone tried taping a colored but translucent tape on the front sensor? It will fool the mirror to think the front is darker and make the back more sensitive.

 

I was going to say a similar thing but even easier. Just use a whiteboard marker on the front sensor so you can remove it when it doesn't work well or too well.

 

I'm going to put a piece of black electrical tape over the front facing mirror sensor when I get the chance.
I hardly ever drive the Prius at night- but when I do- I'm immediately reminded of the poor performance of the auto-dimming mirror in the Prius.

 

I have found that dimming the dash lights helps the rearview dimming of the mirror

 

Really? I thought the mirror is standalone and not in communication with anything else in the car. Are you sure this was not just a fluke?

 

I found a way to "fix" the non-dimming mirror in my 2012 PiP.

I noticed the mirror is mounted on a "stick" with two swivel ball joints, one at each end of the stick. Most mirrors are swivel-mounted with only one ball joint. So, I played with the position of the mirror-mount stick by changing both ball joint angles together.

I found that by moving the stick so it points to the left (while sitting in the driver's seat and looking at the mirror) as far as it goes, and simultaneously moving it to raise the mirror body up as far as it goes, the angle of the mirror becomes a li'l more perpendicular to the rear window. Additionally, the repositioning moves the rear-pointing sensor just a bit higher. Together, these small changes are enough to make the dimmer work automatically.

I've driven now for two weeks like it, on freeways and on streets. It consistently works for me. Good luck!