Auto HeadLights Sensor - Where is it? [Archive] - Bimmerforums

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mniemiec

01-15-2009, 01:36 PM

Guys, where is the sensor for the auto headlights? It seems to be acting flakey last couple days and I am wondering if there is something blocking it.

rdadhania

01-15-2009, 02:10 PM

It has to be in the front of the car im assuming...because when I am driving to work each morning due West (sun to my back), my headlights turn on. Im guessing this is due to the shadow that is created by my car with the sun hitting it from the back. It probably tricks the sensor into thinking it is getting dark.

scre103

01-15-2009, 02:31 PM

I believe it's in front of the rear view mirror

raceyBMW

01-15-2009, 02:40 PM

Yeah, its on the back side of the rear view mirror...look at it from the front through the windshield and you will see the sensor. The sensor not only measures light intensity, but also angle that the light is coming from. That is the reason even though it may be sunny in the morning, the lights might still come on.

Kernel Kurtz

01-15-2009, 06:21 PM

I've asked this question before here......

I can see 4 optical sensors on my car - one on the reflective side of the rear view mirror, another in the mirror casing facing forward, and two in the mirror mount attached to the windshield.

I know the car has auto headlights, auto dimming mirrors, rain sensing wipers, and supposedly the climate system can sense fogging as well?

Anybody know exactly which sensor does what?

mniemiec

01-15-2009, 09:22 PM

thanks for the info, maybe there was some snow/mud covering it or somthing.

Beer Goggles

01-15-2009, 09:31 PM

I've never seen mine on when driving away from the sun. They do come on before dusk because the law states they should be on 30 minutes before sundown. I must have a good sensor because the wipers work fine and the auto headlights. The rearview don't matter because the windows are tinted.

mryakan

01-15-2009, 11:14 PM

I've never seen mine on when driving away from the sun. They do come on before dusk because the law states they should be on 30 minutes before sundown.
The law (most everywhere including cali) is 30 min after sunset not before! Also up to 30 min before sunrise.

http://www.dmv.ca.gov/pubs/vctop/d01/vc280.htm