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

Update: Since I started this thread, I have never had any other problems with the emergency braking system. It has performed flawlessly. Maybe a bird just flew in front of the sensor from down low or???

SCARY SUDDEN ACTIVE BRAKE ASSIST MALFUNCTION
 

No, I never asked the dealer about it. Best explanation is that a bird flew directly in front of the sensor. It never did it again and now I have moved onto a 2020 S560. Sorry I could not be of more help.

Stream - my 2019 E300 just did this on a trip between NC and NY. Applied the brakes at about 70mph as I was changing lanes on I-81 in MD. I believe it "saw" the truck in the right lane and braked hard because it thought I was going to hit it. (I was changing from left to center lane...)

I had to step on the gas and override it so that I did not get creamed by traffic behind me. It felt like about a 40% brake application - so not as hard as yours, but a big surprise to me and an unwelcome one at that.

No issues since then and I am steering a bit further away from anything as I make lane changes with Distronic on. I chalked it up to tech that is helpful, but imperfect, but like you, I sure didn't appreciate it.

I agree with you 100%. It’s a great system, but it’s not perfect.

Don't worry much about it. If you are using electronic be ready for it malfunction. Even Lexus have some issues don't mention german cars.

So this braking took place while using Distronic. Was LKA turned on too? Another poster mentioned experiencing unexpected braking while making a lane change and isn't it true that LKA can use the brakes if it thinks the car is leaving it's lane in some dangerous manner?

Tom, in my case, Distronic was on. I don't think LKA would have applied the brakes because I had the turn signal on when it happened. If I understand how LKA works, it only applies brakes in response to a lane marker deviation when the turn signal is not used.

Resolved??
 

That car never did that again in the approx 18 more months I continued to drive it. I turned it in and now have a 2020 S560. The issue was never resolved and the best I can figure is that a bird swooped across the front of the sensor or a large leaf blew in front of it. I did not see either of those things, but they still could have happened. Good luck with your car.

Juliamaree is this problem still occurring? My Gls450 just did this to me a few days ago. Absolutely no reason. Still in dealership trying to determine cause. I am concerned they will not have a resolution.

I've had the same experience only my experiences have been on the tollway. I live right outside of the major metropolitan area in Texas. This is happened to me twice driving down the toll road and all of a sudden the brakes slam on my car fishtails down the road. Last year the sensors were replaced and I was told that it was due to a faulty sensor and that due to the toll road mechanisms that engage my active brake system. That happened in 2019. This is 2021 and the same thing happened to me again on the tollway yesterday July 23, 2021. I was in the fast lane passing doing well over the speed limit as I should not have been all of a sudden my car locked up my seatbelt cinching me in and I was fishtailing very close to the retaining wall on my left. Like you, I instinctively tapped my brakes and it seemed to bring it out of the fishtail but then all the way home this occurred 5 to 6 different times, I finally exited the toll road and had to take the back roads. I immediately went to the Mercedes dealership where I purchased the car and the gentleman that greeted me thought that I have been there a few days ago with the same problem he confused me with another customer that was in a black Mercedes E300 mine is midnight blue. I told him I was not the same customer but I had the same problem today and I have the same problems with sensors that will replace almost a year ago. My car is a lease car now I'm very frightened to drive it even if I'm going to replace the sensors again. My car is in the shop they're taking a look into it. I am seriously considering speaking to an attorney to get me out of my lease agreement so that I can get a different car without the auto brake system. I don't know of anyone that has had an accident due to the sensors yet and I don't want to be the first one. This is very very dangerous I was so shaken yesterday I was so upset I shouldn't have to go through this in a $65,000 vehicle that I chose for safety.

Wow! What a mess! I would be freaked out as well. That said, trying to find any sort of a luxury or even near luxury vehicle without Automatic Emergency Braking is going to be difficult, if not impossible. Do we know if something like these episodes are recorded on some onboard “black box” in the car? I think if this happens again, you should pull to the side of the road and have the car towed to your dealer. Please keep us all posted and best of luck getting this resolved.

Brake assist malfunction
 

Thank you for replying as I am still so upset about this and I was not even driving that fast (about 25-30mph). I was very sure of what happened as I had just passed a drop in speed limit to 25mph and very aware of the speed trap it presents. Fortunately there were no cars in front or behind me. I was not near an intersection or any cars parked on street. No one was even on the sidewalk. It literally happened out of nowhere. My car flashed red warning with beep, sharply braked and tightened my seatbelt. It all happened in an instant. I sat in the road momentarily in shock and looking around while trying to release my shoulder restraint. I had a dog (in a crate) in the back, and I immediately thought about what could have happened if I had been rear ended and became even more upset. I was emotionally off the rest of the day from the experience and am still very upset as I keep imagining what would have happened if I was going fast (like your situation). I also think about road rage that occurs too often from nothing, thinking someone would think I stopped abruptly to send a message. Try explaining that my car did it on its own to anyone!
Dealership has my GLS450 and I have heard very little back since Tuesday. One phone call saying that they are sending info to engineers. I asked about my incident recorder in the car and the mgr said only a few faults showed up but nothing related to my incident. One related to a garage door. Interesting as I do not use a garage door opener through my car. But he said the engineers will ask for more information that perhaps he cannot see on his side. I was sure that it would have recorded this incident, but now I am worried as it doesn't seem to show much except for something that doesn't even pertain to my car.
On another note, I purchased this car in April 2021. One month after, my entire front panel went out on me. I was in Michigan and had to drive home without any use of the entire panel. Fortunately I know old school driving. The module was replaced but since then my navigation is completely useless and malfunctioning. Most of the time doesn't recognize address. Sometimes sends me to all parts US but not what I need. Once I finally get the correct address it continually tries to reroute me off highways and tollways (and no I do not have that checked as requested, I check every time). Reroutes me even when the location is within my sight. This has been confirmed by other people in my car watching the car taking me in circles. I have called twice on this with very little explanation and no resolution. I have had to drive to NYC and NJ using apple carplay navigation as I cannot trust the navigation in my car. Same as you, I am about finished with this car three months in. Need to break the lease. I feel safer in my 5 year old jeep.

I am going to file a complaint on the nhtsa.gov website with regards to the abrupt braking just incase this is happening to other people and they are looking for information. Perhaps you will want to do the same. Please keep me posted on what your MB dealer says.

Sorry to hear all of you experiencing these issues. ADAS is meant to help prevent an accident or mitigate the impact of one instead of increasing the risk of causing it. Since it is a safety issue, I think it is reasonable to ask the dealership to not toss the car keys back to you unless it is fixed. Active brake assist could be disabled temporary so the system doesn't intervene but buying a vehicle from a brand that is known for safety, and especially paying all the extras for these safety systems to begin with, disabling the systems isn't really a solution. Either way, if you do you want to disable it, you have the option, the setting is located in the Assistant menu under Vehicle settings in the infotainment. You can set it to Early, Medium, Late or Off.
Good luck to you all in getting this fixed, execute your rights and if you live in the USA, perhaps even start a lemon law claim if you meet the criteria.

I have had this sort of malfunction on two vehicles that I have had with this technology from different manufacturers, 2014 Jeep Grand Cherokee and 2017 Lexus LS460L. It is indeed very scary. Including my S560 I have had 6 vehicles with this tech, 2014 Jeep Grand Cherokee, 2015 Kia Sedona, 2017 Chrysler Pacifica, 2017 Lexus LS460L, 2020 Chrysler Pacifica, 2020 Mercedes S560.

I think this kind of malfunction is just always a possibility with this type of system.

Automakers need to find a way to perfect the technology for autonomous vehicles. Since humans can't intervene with the system on vehicles like those. Although technically computers make less mistakes than human drivers but still...

It will improve, this technology is still very young.

That's true, it certainly will improve but I think adaptive brake assist first came out on a Mercedes back in 1998, I am not too sure.

No, the first distronic systems came out in the W220, but full speed distronic where it would bring the car all the way to a stop didnt come out until the W221, and autonomous emergency braking didnt come about until 2009.

I see. I learned something today, thanks : )

I have the same issues with my 2013 E350 wagon. I have filed a complaint on the NHTSA site and would encourage others to do the same. I have the same package on my Audi A6 and never experienced any false alarms or braking without necessity. Clearly, this is a defect!

I started this thread with the one and only incident I experienced and that 2018 S560 is long gone. We have a 2019 E450 Wagon, 2019 SL450 and 2020 S560, all with the same systems and have never had another similar episode. That said, the experience was truly shocking and now that others are telling similar—but far worse in some cases—stories, it really drives home the need to make sure these incidents are reported. I can’t imagine what would happen if this took place on an icy, mountain road or in heavy but fast moving freeway traffic. Super dangerous, to say the least.

Wondering where you are with this issue? My dealership just got back to me and expected response, "cannot duplicate action" and "refer to user manual for reasons system may activate". Svc manager told me to call their Customer Service CAC to file complaint which I did. 1-800-367-6372
Not sure what happens next.