DDGator

I've had my 2018 GLC for about two months. I don't have the Distronic driver assistance package, but have the standard collision prevention system.

I am noticing an increasing number of "false alarms" with the system. I will just be driving along with no traffic near me and the system will alert and beep -- usually only twice -- and then stop. The system has yet to engage the brakes on one of these false alarms, but it is disconcerting. I have one that occurs near the same point in my neighborhood on a regular basis, but other times seem more random. I drove about 50 miles yesterday and had 3 false alarms (none at the usual spot). Anyone else have an issue like this?

openwheelracing

Possibly to alert you to wake up. We're you swerving and driving erratic?

DDGator

No, I have seen that warning once. It comes up on the LCD screen between the gauges with a cup of coffee and suggests you need rest...
This is definitely the forward collision prevention alarm.

frandumont

Last winter, I have the same problem (the GLC put the brake on highway when I overtake one car) , but after wash the car, the problem is resolve. I think if the sensor is dirty, they make some false alarms.

DDGator

My car is always pretty clean, but definitely worth checking. Where is this particular sensor?

Thanks for the input!

frandumont

The sensor in on front bumper and I think under the side mirrors.

fabbrisd1

The Collision Prevention Assist uses the same frequencies as other "highway related" instrumentation - including traffic counters - and normally it's other electronic equipment that can give you "false" beep - I have never hear any reported false emergency breaking.

Keep the beat !

frandumont

After 2 beep, the emergency breaking is apply. But, the functionality can be desactivate (beep and emergency breaking).

Senatov

DDGator

What is disturbing about this... My wife's 2016 Toyota RAV4 also has smart breaking. I know it works because I've seen it happen (when she is driving). However, it has NEVER, I mean NOT EVEN ONCE in three years had a false alarm the way my MB does almost daily.

Southern_Benz

Daily is an issue, it shouldn't be occurring that often. My 2016 C300 gives me alarms occasionally, but it's not out of the ordinary. Usually happens when I follow close as someone is getting into a turn lane. I know they're turning, so I'm pretty close behind. In those situations, even though I'm out of the way, the system thinks I don't see it, and it will alarm me.

If you're experiencing false alarms on a daily basis, something is wrong with those sensors. Going to be hard to address, as you'll need to do a ride-along with a dealership tech to prove what's happening.

DDGator

Just to be clear, if there is a car in front of me when I am too close, I don't consider that to be a false alarm. By false alarm, I mean 2-3 beeps of the system when there is not a car or obstacle in sight.

I should keep track exactly, but it feel like about once a day or at least every other day (in different spots) and I drive about 50 miles per day.

Chrisk03

Try to keep track when it happens and post back on the scenario.

I don't believe I've ever had a "false alarm" and mostly recognize why the system "beeps" when it has for me. I do remember one "beep" when there was nothing around/near me, but I was going thru a yellow light, so just assumed it was that. If you are getting multiple false alarms, I would have it looked at, as well.

Bert.DS

Yes, I get those too. Usually in a turn, when something made of metal (thus radar-reflective) is at the outside of a turn. The system thinks I am approaching it too fast, I guess.

DDGator

I am going to start making some notes. It is usually when I am literally driving straight on a road with no car immediately in front of me or in the adjacent lanes. Will report back.

CB949

Hi All,




I started a thread so we can get a head count on people with this issue, across different platforms. If your car's having this problem, please post here:




https://mbworld.org/forums/mercedes-...ml#post7833418

RSNovi

There is one overpass that I drive under which often triggers a false alarm.

openwheelracing

Itnonly happened when I drove along lakes in Austria due to narrow winding streets, once the car got to California, never falsely triggered.

Then again, I was driving aggressively so of course I expected the warnings to activate.

VancityGLC

I'm facing this issue almost on daily basis. It's very annoying. The alarm (red triangle) and the noise come when there is no one around me and nothing in front of my car. Has anyone took their cars to the dealer for a fix? I've tried once and they said they have to see the problem to fix it!!!

frandumont

With the last software update on december, is it less often. But, you can adjust the sensibility too.

VancityGLC

How do I get the update? Thru dealer?

frandumont

When I make the scheduled service on mercedes dealer.

CB949

Here's the update on my situation:

-I have video proof of these defects.
-I filed a claim with the BBB 'lemon law' department. Despite the proof being clear, the arbitrator dismissed the case because of an unrelated issue (short version: in addition to this defect, a different defect caused minor injury, so the BBB dismissed the whole thing as an 'injury incident').
-I don't have the time or energy to deal with lawyering-up. The case is cut and dry, but I am just way too busy.

If anyone out there is dealing with these same issues, send me a private message and I am happy to share the contact info of the MBUSA CAC Senior manager who was on my case. I would be happy for them to understand how many people are dealing with this very dangerous defect.

jolugo

The system has issues with stationary objects, overpasses, metal poles, etc. Its the same for all of these systems. So when you approach them, it thinks you are going to crash. There is really no way of fully solving this without using (adding) other sensors. I had the same problem with my last car (ML). It would always go off at the same intersection with a bunch of traffic lights hanging. The current car has the driver assist package and so far it doesn't have those false positives.

CB949

In most industries this would be categorized as 'not ready for market'.

A feature which can do the opposite of its design intent - which can create grave danger for users - should be developed to the point of not having these issues prior to release.

FWIW, my range rover has all the same category of tech and has never given a false positive.

And/or if it's happening in a small minority of vehicles, then when a manufacturer learns of its customers having these issues, they should take action to remedy it for those customers.

Their decision to shrug and walk away from customers who are having this kind of issue, just to save a few bucks, is really hard to understand.