Auto dimming mirror dimming during the day?

[s4boost]

just bought a b8. The auto dimming mirrors seem to go full dim during broad daylight. Is this a setting somewhere? Anyone else noticed this?

Green light is "on" on the rear view mirror. And this happens as soon as you start the car.

[gambera]

Fully dimmed compared to night time?

If the sun is low at the horizon and behind the car, it dims little bit to light blue-ish color but nothing like nights. If car behind you is on high beams during the day, it doesn't affect dimming.

[s4boost]

To be more specific, the mirror goes full dim as soon as I start the vehicle. The only way to disable it is to turn off the dimming function.

[gambera]

That's weird. Sensor maybe. Sounds like trip to the dealership if you still have warranty.

[turbophreak]

Wonder if it's the time zone thing. In the manual it tells you how to set your zone. I guess it could be that if it thinks it's night time when it's actually day time the mirror might dim because it just mistakes sunlight for headlights.

[s4boost]

Added a picture.

[turbophreak]

That looks pretty freaking sweet! But yeah, not how it's supposed to work. So I'd try recalibrating the rear view according to the owners manual first and make sure the zone is right. I think that only applies to the compass but you never know.

If that doesn't work there are two light sensors. One is on the front of the mirror facing the windshield and the other is on the rear of the mirror facing behind the car. The forward facing sensor detects night and day. The rear detects headlights. The mirrors are only supposed to dim if the front sensor detects no daylight but the rear sensor detects light. If something is covering the front sensor or its gone bad it thinks it is night time and any light received at the rear sensor will trigger the dimming, including daylight.

Gentex makes good stuff, never seen their mirrors go bad but I did know someone that had the same problem because they put a parking pass sticker on their mirror accidently covering the front sensor.

[s4boost]

Ah. I c. I just noticed it doing this at dusk/night time as well. Seems like if the green light is on they just black out. I was wondering if there is any coding for this. Oh, and I did recalibrate.

[MrFunk]

That happens if I'm in the garage facing inside and I open the garage door during daytime. It's brighter behind (outside) me vs in the garage so it dims thinking it's dark out and there are bright lights behind, but the second I reverse out of the garage it lightens up. I'm betting your light sensor is effed up. Are your headlights on constantly?

[s4boost]

What's weird is that they aren't always on. It's just the mirror on the fritz. I just went for a drive and it went completely dim at first then lightened up. I don't know if it's something someone messed with in vag com, or if the mirror needs to be replaced.