wamochi

Sorry if this has been covered before in another forum, but I can't seem to find an answer.

Can the auto headlight sensor be turned down a bit? I find that it's really way too sensitive on the GL. Didn't seem to have this problem on the 2008 E63 we traded. Is there a way to turn it down, or can someone tell me where is the sensor and maybe I can check to see if it's dirty or something ...

For instance, it's been SUPER SUNNY the past few days in So Cal, like blinding sunny by 8am when I'm taking my son to school. The lights stay on until about 9:15 I would say. Same thing with the afternoon. I find that they start coming on around 4:30pm, even though there's not a cloud in the sky and it's very sunny. No other car around me has their headlights on. On rare occasion I see a newer model Benz driving around w/ their lights on as well, so I don't think it's an isolated problem, but there has to be a way to tone it down?

Sometimes I think it's time-related also. Like lights HAVE to be on before 9:30am and after 4:30pm, even if it's really bright and sunny out. I know that's nuts, but I just don't get it.

BTW, this is for a 2011 GL450.

Fourdiesel

Have the dealer check the sensitivity of the light sensor (let them find it!). The lights shouldn't be coming on with ANY sunlight present.

43221B

They do the exact same thing on my 09. I've concluded that it is purposeful so that your vehicle can be seen in morning and late evening glare. I'm in Ohio and the lights will not come on on a cloudy day (we have a lot of those) at the same time late in the morning or early evening as they would in bright sun. A couple of months ago I started noticing it. Every time there was a lot of glare I would check to see if they were on and sure enough, they were. That's just my guess.

wamochi

i think you are on to something re: the glare. b/c if i am driving away from the sunset in the afternoon, even though it's sunny out, the lights come on. i suppose from a safety standpoint, the person in front of me looking in their rearview mirror during sunset would not see me as well if i didn't have headlights on ...

it's odd that the car can measure that -- i thought it was pretty straightforward, meaning sunlight present = no headlights, but i guess the system is more complicated than that ...

QuadBenz

You can't forget that these cars have dusk sensors. That could be why it feels like the need to turn the lights on when the sun is out, however not on a cloudy day.
I've noticed slightly similar behavior as you both.

Texas993

I notice the same behavior on my '10 GL and '11 E. But why is it a problem?

justthebest

This doesn't happen on my '09 550

wamochi

it's not a problem i guess, except i am the only person driving around with headlights on in broad daylight. it is really sensitive. it's going to be 80's and sunny this week and i'll take a picture of the car w/ headlights on in total sunlight with not a cloud in the sky sitting on my driveway at 915am.

also, i cannot just turn my knob to "0" because if you have the DRL feature activated (which i do for the LED DRLs), when you turn the knob to "0" it does nothing. it still stays on auto and the headlights remain on. i googled this strange occurrence and apparently it's normal. you must deactivate the DRLs in order to be able to manually shut off the headlights...

wamochi

here are some pics taken around 9:00am this morning. it is very sunny today, no clouds. it's so bright that the iphone can't handle it and you can't even see the headlights on in the pictures, but they ARE on along w/ the DRLs.

so this is "normal"?

Brocktoon

You must be the only guy in the whole world whom can see his own headlamps whist driving. I personally drive around with all my lights on, all the time. Can't hurt being seen, right?

wamochi

can't see them from the outside of course, but the indicator in the instrument display. and it's gal, not guy

MBZFAN55

I just took delivery on a 2011 GL550 and one of the first things I noticed was the lack of sensitivity sophistication on the GL headlights compared the the 2008 CL. The GL drives through a shadow and the headlights come on. The CL is almost mystical in how it determines when to go on and off, making me think that Mercedes has at least two different systems in place.

jcbutta

Oooooohhh, scary. Just in time for Halloween.

wamochi

yeah i think that's what's frustrating. the 08 E was perfectly fine. oh well. sounds from the few postings here that this is normal behavior on the '11 GL.

i was driving back from the doctors office at 3pm today and it is 87 degrees and 100% sunshine today and the lights were on the whole way (20 miles). i wasn't parked in a garage and didn't go thru any tunnels, etc.

Brocktoon

nothing is obstructing the sensor, is it? Like a parking tag, bird poop, sticker etc?

wamochi

i don't think so. where exactly is it?

Brocktoon

My car is not with me right now, but I recall it being in a little red tinted window on the windscreen above the rear view mirror. It could be on the dash, but I don't think so on the GL. pretty sure it is above the mirror with the rain sensors. Are they working? If you have the car with you, have a look.

mjohnb

My '11 GL does the same thing - the headlights are nearly always on. I even tried to switch them to the off position, rather than automatic, and they still stayed on...

blittle

Hey guys..... Do a search for thread entitled "Headlights on Auto?". Go to about the next to the last post and you will get the best explanation as to what is happening......... Not the best engineering in my opinion BUT does explain WHY it happens.

Mikeee

Am I the only one to not see how is that a problem? I drive with my lights switch on always. Not to mention that in most of Europe they have to be on for most of the year anyways.

Mexx merc

It's located on the dash, at the middle, very close to the windshield.

robalo220

Who cares? I cant tell when mine come on unless I get behind a pickup and can see the reflection in the tailgate. That is why you put your lights in the mode that your lower lights come on during the daytime. Ever seen a Volvo or a GM? They have the daytime headlights on 24/7. For visibility. Oncoming traffic can see you better. Motorcycle? Again 24/7. Come on manufacturers have had these sensors for decades. Drive in a shaded area and the lights will come on (lots of trees). Drive in a tunnel? Lights come on. Does your car drive and function properly? If so, great. If not go to the stealership and have it checked under warranty. Life is short, enjoy it without worrying about your headlights.

Peace

YasS

Anyone find a solution to this? My W211's headlights are on and off every time I'm under an overpass. I like to keep my headlights on auto and turn down the sensitivity, but I can't find it in a W211.