sg021

Since I've had my GL I've noticed the automatic high beams are not that reliable. I drive sparse back roads early in the morning, and noticed a couple of things that tend to happen.

Sometimes won't come on, for instance a long, straight, empty road didn't trigger them. There was a traffic light nearly a mile away and some mailboxes with reflectors. Is that stuff enough to confuse it?

Sometimes it comes on when you don't want it to. I was following someone around a curve and they came on.

Is this typical or not? I do not have distronic plus, does that improve the system? The only previous experience I had was with an MKC that worked really well.

Mike450

Sounds about right. The system definitely errs on the side of caution when activating them. I typically just reach down and one click right on the light switch if I'm on a road where I need them often.

I wonder if there is a sensitivity adjustment the dealer can make?

fabbrisd1

If you have the "Inteligent" headlight system - in Auto high beams will not activate under about 55 mph - regardless of outside conditions -

On the Standard or Intelligent system - best to review the applicable pages of the Owner's Manual regarding the auto-parameters.

Yes - going "up-a-notch" to manual control for hi/lo is always a decent options.

Keep the beat !

Dog hauler

As Mike said, just turn the headlight rotary switch one click clockwise and the high beams revert to manual. I just leave the switch there. The lights still come on and turn off automatically. Truth-be-told, I don't know what the lights on full auto do except make the high beams pretty much non-operable.

jbattan

I too have found that they have erratic operation on both of my MBs. I've had the dealer check it twice and he hasn't been able to replicate the issue. I find if I push the stalk to regular beams and then back to auto high beams a couple times, that seems to fix it. Or, turn off and on the lights with the rotary dial, but that's obviously dangerous when hurtling down a country road at 55 miles an hour.

Lone Star Benz

The auto high beam system in the GL works well compared to the auto high beams in our Land Rover we had prior.

I still prefer manual operation on a semi-busy road, but on a rural road with only the occasional motorist and few other light sources, I found that they do quite well. They perform better than I expected.

Dalema

I think it is around 35mph that the feature disables itself.

Elric99

They actually changed it between years. Starting with the 2014's the feature enables at a lower speed than the 2013's. I think it might be as low as 20 mph, but can't recall for sure. Overall mine work ok, but yes sometimes turn off when they shouldn't due to spurious reflections.

sg021

Thanks everyone for the input. I decided to actually go look in the manual, and for MY14 the feature is defined as:

If you are driving at speeds above
approximately 16 mph (25 km/h):
The headlamp range is set automatically
depending on the distance between the
vehicle and other road users.

If you are driving at speeds above
approximately 19 mph (30 km/h) and no
other road users have been detected:
The high-beam headlamps are switched on
automatically. The high beam indicator lamp in
the instrument cluster also lights up.

If you are driving at speeds below
approximately 16 mph (25 km/h) or other
road users have been detected or the roads
are adequately lit:
The high-beam headlamps are switched off
automatically. The high beam indicator lamp in
the instrument cluster goes out. The_
indicator lamp in the multifunction display
remains lit.

So it activates at greater than 19 mph, which I'm not surprised about based on my experience. Another section noted that the light sensor is responsible determining if the road is clear, so I guess it just can't distinguish between light sources well.

My only previous experience was with an MKC, which has a forward camera. It's very good at realizing what is a head light or tail light, and what is irrelevant like reflectors. It's a shame the surround view system front camera couldn't have contributed, although I guess it may not have enough range to be useful for that.

Newbie_2_MB

I was up at my cabin this weekend and the roads are dirt. I noticed the auto high beam wouldn't activate. I'll have to do the "one click to the right" when I'm on these roads and go to manual mode. Thanks!

KatanaPilot

Can you guys with a MY14 or later confirm that your auto high beam activates at 19mph?
Mine is a MY15, but my auto high beam activates consistently at 35mph and goes off at 30mph. Mine behaves exactly like the MY13 manual describes.

The dealer said they will update the software, but nothing has changed when I got the car back. I suspect it is a setting somewhere only the dealer can access, and I need more information before going back to the dealer.
Thanks in advance!

jacobsung

I've noticed that if there a road sign that reflects back at me, the auto high beam would turn off.

Jason B

There should be a way to adjust the sensitivity! All places around the globe aren't the same. I had an older car years ago that had this standard and you could adjust the sensitivity,