exx1976

I have a 2004 545. Where is the photo sensor located for the automatic headlights? I think I need to clean mine, since the past few days they've been turning on in the middle of bright sunny days... ??


Thanks!!

mini_me

Could it be located in the rearview mirror assembly?

BenAnd

Hi

It's located together with the rain-sensor ( rainsensor & lightsensor is in the same unit ) mounted on the inside of the front windshield together with the rearview mirror , it's the "clear" point in the "black" aerea when you look at the windshield form the outside

MacSid

You may also be experiencing the so-called "blue sky effect" that can trick the sensor into switching your lights on. There have been a couple of discussions on this thread about this, all of which can be reached from:

Adaptive Headlights Discussion

I've had similar problems on and off and taken the car into the dealers multiple times to have it looked at. they have tried a multitude of things, from changing the sensitivity of the sensors to software upgrades (not to mention much cleaning of the sensor areas), only to have the instance of lights coming on in bright sunshine continue, apparently at random.

On the umpteenth service visit on this, one SA dug out and showed be a BMW service bulletin describing "blue sky effect" (this was about 8 months ago) as an explanation. I do not recall the exact explanation but, from memory, it had to do with differences in the various spectra of light. Sounded plausible, even though it still made me wonder why Renault seem to have got it spot on on the Megane, but BMW seem to struggle...

exx1976

Interesting. My old Pontiac never seemed to have this issue.

Also interesting, the drive in to the office today was rather overcast, and I only got DRLs, no headlights. Meh. I'll ask the dealer when it's in for the next service.

Thanks guys!!

melimel

your avatar is funny.... very cute and original.. lolol

this could explain the "rearview" comment... lolol

mini_me

It is taken from an advert. of my other passion; My italian V twin bike, an Aprilia.

Their advertising campaigns are really very funny and IMHO good.

iCharles

This would always happen in my E60. But the funny part about it was most of the other E60's I saw on the road also had their headlights on at the same time. It was like BMW sent out a wireless signal, "Ok people, lights on."

pigapumbu

Blue sky effect is mentioned in the manual so I am surprised the BMW service people took you on a long process to simply explain whats in the manual.

As for the autolights, I just stopped using it all together. Its a total waste of time IMO. Much like the rain sensor. BMW design logic has gone to pot there. I only turn on the auto lights (position 3) when I turn off engine just so that when I return to the car and unlock the door, the lights come on slowly which is really cool. Pity BMW engineers decided to be stupid and not have that cool feature when the lights position are in 0.

As soon as I get in the car, I put the lights swtich back to 0 as I don't need the xenons blasting away in bright day light. Other people will think I am just showing off my xenons like some audi drivers who insist in driving with their xenons when the sun is blaring down on us.

cheers

MacSid

Interestingly, the first time I had complaints with the lights, they made adjustments that all but resolved the problem, but left the lights a little more ponderous in turning on in tunnels than I was comfortable with. Car went back in, more adjustments made, software upgrade, and things were fine.

About 6 months after that (8 months ago), I started having problems again after turning off the DRL functionality in my iDrive - basically winter was over and I didn't want my lights on all the time. This time, it was adjust, then adjust again, then "your light sensor is faulty, we'll replace it under warranty", and then it really went pear-shaped and that's when "blue sky effect" came up. The SA also told me that there had been an increase in the number of complaints, resulting in a Tech Bulletin from BMW.

Basically, subsequent part and/or software upgrades seem to have made things worse, and my rain sensor seems to be going that way too, but that's another story for another thread ...