CB949

Hi Folks.

I've seen a few posts regarding this issue, including others who have experienced the kind of life-threatening malfunctions of this system as I have. I also saw that at least one poster here has filed a complaint with the NHTSA.

And so far, it seems like all of us are getting the same response from MBUSA - "operating as designed". So let's see if we can get some strength in numbers going, to help give them a good reason to do the right thing for their customers.

Here are the specific situations I have personally encountered since taking delivery of my e400 wagon in June of 2018:

-Two episodes of random "brake slamming" when driving on a straight clear highway.
-Several (10+) episodes of small road irregularities (bumps/dips) activating the system during low-speed in-city driving.
-Almost 100% activation of the system when pulling into my own driveway (!!!), which has maybe a 6" rise in height from street level, over ~3' in drive. This one is the most troubling because the system not only brakes, it kills the accelerator, often leaving the car stuck, perpendicular to traffic, and we live on a blind curve. The only remedy is to keep backing up and trying again, over and over, to try to find an approach angle that doesn't activate the system.

Mercedes has looked at the car three times. Each time, the answer is the same, "Operating as Designed". I can't wrap my head around how they can still be taking that position when the most basic functions of the car - going and stopping - are being over-ridden by false activation of what is supposed to be a safety system. I don't know if they are just waiting for someone to get hurt by this design flaw (if it is "operating as designed", this is a very serious design flaw), or what.

Who else out there is having issues with this? Is it happening in any other situations?

I understand it's not 100%, so before jumping in and saying "mine works perfectly", please know that I understand that while it's not an issue for everyone, for those of us who are experiencing this issue, it's a very big deal. And I also understand it's new technology...but based on my experience, it ain't ready for prime time!

TugboatBill

I have some questions - is this part of the Driver Assistance Package or is it in all E series? Can it just be turned off?

CB949

Per both MBUSA and "Germany" when they ran this up the flagpole, no.

wagonsrock

My May 2018 E400 wagon has never exhibited the issues you describe - which sound really awful. If I leave the lane departure warning system on the car will brake quite violently, but only if I've drifted across a line, as sometimes happens when I'm driving on two lane country roads. Its annoying, but I usually leave the system on anyway. I wonder whats different in your car, and how common this problem is?

sackboydad

I’ve had a few times where my E450 Cab has gone psycho and one-side brakes for, seemingly, no reason.

But of course, I’m sure the car DID have a reason — I just don’t know what it was. I do know that it saved my bacon once. I didn’t see someone go through a cross street’s stop sign, on my right, while I was doing 50mph. Before I knew what was happening, the car pulled my seatbelt tight, raised my seat to the full upright position (it was just a tad back but I sure felt it love), and I felt the right bolster on my seat instantly push me to the left. At the same time the car one-side braked to pull me to the left (I assume the sensors scanned that there were no cars in my blind spot in the left!)

I do feel the car can be a bit sensitive if you dare even touch the yellow line. Sometimes on curvy two-lane roads it’s just tough. And I haven’t yet tried to deliberately pass someone on those same roads. I have to admit I wonder if it will freak out and try to pull me back to my lane... maybe the turn signal makes all the difference?

Diesel Benz

Do you really need to back up after this incident? Applying brakes, releasing and accelerating should be enough (cannot verify, cannot make the car behave like above). It should be something like braking kills acceleration, if you press the accelerator pedal and brake, engine power is lost but if you keep braking, release the gas pedal and press again, the car gets going even if you kept braking all the time (of course cannot brake at full power).

The_Judge

I've had the brakes on my 2018 400C activate while driving on surface streets a few occasions over the past 16 months, apparently caused by minor irregularities in the roadway — all were merely instantaneous, on and off in a half second, a minor annoyance. It has also activated on the freeway or city street if it decides that I'm approaching a stopped vehicle a little too fast for the distance, and it has activated at times when I've been backing out of my garage onto the street if an approaching car is within range. IMHO that's a good thing if not always necessary. Better safe etc. etc.

TPAbnz

I've tried to activate it by placing 5' tall cardboard boxes in our office parking lot. The car will hit the boxes in front and behind. Dealer says normal operation; at low driveway or parking lot.speeds and you only get Parktronic proximity tones and COMAND display.

Our previous Porsche Cayeene would brake and never roll over something (like the size of a child) in reverse. Should I have this checked at another dealer?

The_Judge

That's certainly not true when I'm slowly backing out of the garage onto the street and the sensor detects an oncoming car. Perhaps the dealer is bull****ting you so you'll go away (a shocking thought I'm sure).

YasS

You gotta make a video of this and post it on YouTube.

bytemaster0

This is normal. Cardboard boxes are not sufficiently RADAR-reflective. Otherwise, leaves and lightweight obstacles could trigger AEB. If you really want to test this, use the 5' cardboard boxes and line them with a couple layers of aluminum foil. Works perfectly.

bytemaster0

Have you considered a Bridjit curb ramp system? This might not only assist your AEB issues, but also save your suspension some considerable wear and tear. We have a set of them, along with an extension, and they are amazing. I've created a custom mounting system for them that prevents them from scooting, and they've been phenomenal. Also, you can definitely turn off AEB, there's a system setting that lets you activate or deactivate it - though you shouldn't ever need to. My bet is that there may be a calibration issue. See if you can get your dealer to perform a "Distronic Normalization" procedure. As the Distronic systems are all interrelated with AEB, this could offer significant assistance.

CB949

Yes. The first time it happened to me I tried to accelerate through it but revs got high enough to get a little scary with a concrete wall 15' ahead.

Yeah, probably. But the funny thing is, MBUSA isn't disputing that this happens, so we're kinda past the point of "providing evidence". They agree it's happening, the field guy took his own video. And I think they know it's a problem because after this they stopped answering my calls and emails and instead sent me a very formal letter stating the system is "operating as designed" and was "not eligible for refund or replacement" (I hadn't asked for either...).

Thanks for the ideas. We don't have a curb, it's cut and angled no hard stop, so it looks like all that ramp system would do is raise the height of the drive slightly. Cool thing for people who do have a curb at their drive, though! Re calibration, They've tried "every" (per them) calibration option. Possible that they missed the one you're mentioning but seems unlikely given that MBUSA, CAC, etc are involved at this point. I can try again; this will be attempt #4 (plus the field visit, so 5, I guess).

They told me it was impossible to turn it off. I guess if I could that would be a possible solution. Though I have to say, the idea of buying an $80K car, in part because it has all of these amazing safety systems, and then having to deactivate one of the key safety system completely because they can't get it to work right...that seems like a pretty rough solution from a customer perspective.

CB949

I wonder, too. The "how common" question is why I posted this. I found some others in other models' sub-forums talking about it, so I know it's not just me, but does seem like a minority issue. I am sure MB would hold a very high bar for any kind of recall on an issue like this. "A few customers" is never enough until something really bad happens to one of them. I'm hoping I am not that person.


And in terms of "What's different", I can't help but wonder if it's the same root cause that led to my COMAND system going fully-dead after 24 hours of ownership, and requiring a full replacement of the system and breakdown of the interior to chase wiring problems. !!!

TPAbnz

Is the system capable of detecting a child?

mickhoog

in the first 100km of my car, i was driving down the road and it just slammed on the brakes, but i was scared and pressed the accelerator so i wasn't hit from behind. The road was clear. I hadn't really trusted the system since then. So i would if it happened again, press the accelerator

I should have let it come to a full stop and it would have issued a fault code, but it didn't.

You can ask them to flash the ECU.

CB949

Thanks. With my situation, the accelerator doesn't help - the system kills it. Engine revs but....

The notion that we're buying cars that cost this much, and have to think things like "I should have let my malfunctioning car come to a full stop in traffic so the manufacturer can diagnose the problem" - seems really crazy to me. These are supposed to be systems to *increase* safety...a driver having to expose themselves to additional risk of bodily harm just to troubleshoot something the manufacturer should be all over...that is nuts.

The_Judge

As with the Boeing 737 MAX, it seems as if manufacturers these days are unwilling to properly and fully test systems before selling them to gullible buyers. Cash is [still] king in the corporate work. I shudder to think about so-called self-driving cars taking over the streets and highways.

Mbracer26

Film it and send it to the news. The news loves **** like this. just look at poor telsa.

The_Judge

Article related to this thread: https://www.marketwatch.com/story/gr...teid=rss&rss=1

2012 merc amg

It sure sounds like something messed up with your car maybe relating to when the dealer replaced the command system. Between my two E450's one been 14000 miles so far with no issues like this although I do leave the lane assist feature off all the time. I don't like the feeling having my car push me back into the lane. Have you tried it just leaving the lane keeping assist feature off? Might be worth a try. If it were me and things like this were happening and the dealer claimed it was all normal and you even tried turning everything off and still no remedy I'd probably just dump the car for another. I do know a lot of the programming on the 2019's seems a lot better, thats one reason I dumped my 2018 plus I like the new steering wheel a lot better too. I did not like some of the scary behavior the adaptive cruise exhibited on my 2018 like following cars to off ramps getting off the highway when I wanted to go straight, my 2019's don't do this. I felt like I could not trust the 2018 and thats a bad feeling owning a car that is that way.

CB949

My car actually doesn't have lane assist, as far as I know. Also no adaptive cruise. This is purely the emergency braking system kicking in when it should not.

Ongoing problems over the weekend...driving I-5 between SF and LA, perfectly straight road with no other vehicles nearby, the parking alert radars start flashing red and orange like I'm parallel parking right next to another car. ???

And MBUSA has gone silent on me. Pretty shocking level of disinterest in resolving this from their end.

I would definitely dump the car but I'm a year into a 3-year lease and really not interested in taking a $10K bath because these guys won't handle this issue.

bytemaster0

The Parktronic system uses ultrasonic sensors. They are programmed a little differently than they used to be, and have a wider field of "view" for the system. I've discovered a number of things to be aware of, especially on the W213. 1 (all MBs with Parktronic): If you're around a very loud, high-pitched sound source (think of a bus suddenly releasing pressure from the air brakes), Parktronic interprets this as its ultrasonic ranging bouncing off a very close object. 2 (just W213 and newer systems): If you're slowly going around a corner (e.g., turning left off a street), and a vehicle has JUST passed you going in the opposite direction, the car still thinks the other car is close by and that you're about to crunch your door into it. Eventually, the system notices the other car is no longer in your way and quiets down. This is in part because Parktronic doesn't have ultrasonic sensors near the doors, so there is a large blind spot. Obstacles are largely interpreted by the closest two sensors, on the sides of the front and rear bumper. The car infers side obstacle information from those two cues. It's actually quite brilliant, but it can be confused.

As for disabling the AEB, it can definitely be done in the Vehicle Settings menu under Assistance Systems. However, you're right. It's a life-saving technology, it should work when the vehicle is on. My wife was 9 months pregnant with our daughter, and Distronic Plus/PRE SAFE Brake on her GLK saved her from an accident while she was calculating a merge onto a busy street. And the same systems have definitely helped me avoid some nasty circumstances before as well. When they're set right, the systems are brilliant. I have noticed, at least with the old W212 that I had, if there is a 1" or so sudden sharp bump on the road (think road construction, where the road is dug out, but the bridge you're approaching is concrete and thus higher relative to the road), the alert will go off. That car had Distronic as well, and didn't put on the brakes in this situation, but it alerted. With the W213, also Distronic, I've had it half-apply brakes once in response to a RADAR ghost, but never full AEB as a false alarm.

One thing to know is that the vehicles not equipped with Distronic use one medium-range RADAR sensor under the bumper. Vehicles with Distronic have three RADAR sensors, two medium, one long-range, in the front bumper and star or in the grille. Those systems are likely able to better assess a situation because of more sensor data. I really hope they are able to take care of your concern. I can tell you that MB goes through millions of miles of testing with these cars, and the autonomous assistance systems and AEB systems have been in development at MB since the 1990s. They really are the best of the best when they are working right.

ak194kt

Same issue here with a 2022 S580

W205C43PFL

We are discussing about it here as well : https://mbworld.org/forums/e-class-w...ke-assist.html