Auto-dim mirrors always dark and headlights always on in auto-mode

[Matticus91]

Having a weird issue that I'm guessing is related to my windshield being replaced recently (by certified BMW collision center). When my headlights are in auto-on mode, they are always on, even in bright midday sunlight. Additionally, my auto-dimming mirrors are always dimmed now. Any thoughts for a simple fix?

[1and1]

Curious what you learn about this- my auto headlights are way to quick to turn on, and once on will stay on through several minutes of direct sunlight. I've pretty much given up on the automagic part of this business as a result.

[Matticus91]

Originally Posted by 1and1

Curious what you learn about this- my auto headlights are way to quick to turn on, and once on will stay on through several minutes of direct sunlight. I've pretty much given up on the automagic part of this business as a result.

Mine worked great previously, and that sounds more like a sensitivity issue, which you can have adjusted at a BMW dealership for free in most cases

[smrtypants44]

The autodim mirrors use the sensors in the mirror to decide whether to dim, the car uses the sensor behind the mirror to turn on headlights, could the windshield have some sort of coating on it thats blocking the sensors from working? Does the rain sensor work (rain and light sensor are in the same housing)

[1and1]

Rain sensor is a great idea for comparison test! May be that they didn't re-connect everything from that area?

[zx10guy]

The sensors for the autodim for the mirrors are on the inside rear view mirror itself. If you look on the right side behind the mirror itself, you'll see a clear plastic square. This is the sensor that measures the ambient light. The other sensor is on the mirror face that's a small oval. I wanted to test the operation of the auto dim on the mirrors. So I covered up the plastic square with my finger and used a flashlight to shine directly not the mirror sensor.

Not sure if the ambient light sensor on the backside of the mirror also controls operation of the headlights in auto mode.

[Matticus91]

I'll test out the rain sensor and see if that works. They're going to look at it Friday if I can't get it to work myself.

[mackeroni]

I think the sensors are attached to the windshield with double-sided tape. When I had my windshield replaced, I ordered a stock windshield through my BMW dealer. The BMW parts counter guy automatically added new sensors to my order. I asked if the ones currently in the mirror could be reused. He did not know. He always just ordered them automatically if the car was so equipped. So, I asked the windshield installer if they could be reused. He agreed to try. He just had to remove them from the old windshield and use new tape to attach them to the new windshield inside the mirror base. Saved me a couple hundred and I haven't had a problem at all.

I told you this story thinking that your windshield installer might not have reused the sensors correctly, e.g., tape in the wrong place, cables not attached correctly, or sensor window accidentally covered. Just a guess.

Peace...Mack

[Matticus91]

Originally Posted by mackeroni

I think the sensors are attached to the windshield with double-sided tape. When I had my windshield replaced, I ordered a stock windshield through my BMW dealer. The BMW parts counter guy automatically added new sensors to my order. I asked if the ones currently in the mirror could be reused. He did not know. He always just ordered them automatically if the car was so equipped. So, I asked the windshield installer if they could be reused. He agreed to try. He just had to remove them from the old windshield and use new tape to attach them to the new windshield inside the mirror base. Saved me a couple hundred and I haven't had a problem at all.

I told you this story thinking that your windshield installer might not have reused the sensors correctly, e.g., tape in the wrong place, cables not attached correctly, or sensor window accidentally covered. Just a guess.

Peace...Mack

Thanks for the input Mack, entirely possible but I did see all new stuff on the invoices. Still doesn't mean it wasn't potentially installed wrong.

[1and1]

Curious if you've had a chance to look behind the rearview mirror yet? If not I'm hoping you take pics when you do! I'd love to see what you find-vs-what it should be like!

Originally Posted by Matticus91

... sounds more like a sensitivity issue, which you can have adjusted at a BMW dealership for free in most cases

Found the setting in the BC menu and fixed it! Was on the most sensitive of three settings. Changed to the least sensitive and so far it's behaving much much better!

[Matticus91]

Originally Posted by 1and1

Curious if you've had a chance to look behind the rearview mirror yet? If not I'm hoping you take pics when you do! I'd love to see what you find-vs-what it should be like!

Never got the chance, taking it to the shop at some point tomorrow, I did discover that the auto-headlights work however. We had a CRAZY storm today. Also a good test of the BMS cowl filters and the vents in the hood for rain performance.... shit be wet, yo.

Originally Posted by 1and1

Found the setting in the BC menu and fixed it! Was on the most sensitive of three settings. Changed to the least sensitive and so far it's behaving much much better!

Nice!! Glad to hear it was a simple fix

[TheCaptain]

Originally Posted by Matticus91

Having a weird issue that I'm guessing is related to my windshield being replaced recently (by certified BMW collision center). When my headlights are in auto-on mode, they are always on, even in bright midday sunlight. Additionally, my auto-dimming mirrors are always dimmed now. Any thoughts for a simple fix?

Even though it was a certified BMW collision center, I'm curious about the piece of glass they used. Was the new windshield an actual BMW part or something aftermarket? Anything aftermarket could potentially filter certain frequencies of light and that could affect the performance of the sensors.

[Matt@EuroJerks]

Originally Posted by 1and1

Found the setting in the BC menu and fixed it! Was on the most sensitive of three settings. Changed to the least sensitive and so far it's behaving much much better!

What is the BC Menu? I would like to hear more about what you did.

[Matticus91]

Sadly they forgot about me coming in today and I didn't have the time to wait around for hours... Will be going back at some point next week to get this figured out.

Originally Posted by TheCaptain

Even though it was a certified BMW collision center, I'm curious about the piece of glass they used. Was the new windshield an actual BMW part or something aftermarket? Anything aftermarket could potentially filter certain frequencies of light and that could affect the performance of the sensors.

It's all stuff direct from BMW. They aren't allowed to order non-BMW parts.

[zx10guy]

Originally Posted by Matt@EuroJerks

What is the BC Menu? I would like to hear more about what you did.

The button at the end of the turn signal labeled BC. Hitting it will move through a bunch of different options that scroll through the alpha display in the gauge cluster.

[1and1]

Originally Posted by Matt@EuroJerks

What is the BC Menu? I would like to hear more about what you did.

check the new diy-

DIY: Adjust automatic headlight sensitivity

[Matt@EuroJerks]

Originally Posted by 1and1

check the new diy-

DIY: Adjust automatic headlight sensitivity