CB949

The formal documented position of MBUSA is that these incidents fall within the parameters of the system 'Operating as designed'.

I would not expect them to take any action until either someone shines a very bright light on this problem, or someone gets hurt.

My expectation of them having an actual moral compass has been proven very wrong over the past year.

CB949

Been checked out for a while - disappointing but not surprising to see that these issues continue for people.

MBUSA, SF Benz, and Mercedes Manhattan have all been made aware of the issue, up to the level of Chairman. So the minute there is an issue that causes an accident, there is liability up and down their organization.

Cross-posting:

My primary contact was Ed Rouhani at the CAC: https://www.linkedin.com/in/ed-rohani-4a062a5/

I had an unrelated issue with me car at delivery, and he and the CAC quickly stepped up and made it right.

As this issue kept happening, I was at one point offered a substantial credit toward any other new Benz, by Mr Rouhani. When I went to take them up on it, after setting up the deal 100% with my local dealer, the CAC said my offer had "Expired" and refused to honor it. In fact they refused to reply to a single call or email after that.

If anyone wants to contact the CAC to try to get some help, send me a message and I will share direct contact info for the more senior people. All I'd ask is that if anyone gets any traction on them making things right, let me know.

Danny Fabre

2017 C300 with the same issue. I've found a way to deactivate the collision prevention assist plus in the settings menu but it needs to be deactivated every time I start the car. Does anyone know how to change it permanently?

TS MBZ

Ted - 2016 C300

BenzNinja

iTrader: (4)

Trace

I drive a 2020 GLC 300. There have been 3 instances where the vehicle has beeped twice, then romped on the brakes, threw me forward & tightened the seatbelts. Hello whiplash. Every time I was the only vehicle around, and twice it was on the same stretch of road. I am furious, and my neck can’t take much more of this!

I sincerely hope that you get a response from the manufacturer, but I wouldn’t bank on it. This will absolutely be my last MB.

CB949

MBUSA knows about this issue, they don't care. Up to and including the chairman.

They will pay attention after someone gets seriously hurt. I have been keeping a religious paper trail for when that day comes, including my dozens of communications with Sayed Rohani from the CAC, who was my primary contact in trying to get the issues addressed/resolved.

bayside

As someone who is currently shopping for a 2021 GLC, and coming from a Volvo that has on many occasions automatically braked hard for no reason (knock on wood never causing a serious accident), this thread is quite terrifying. Can anyone who is a current owner tell me whether auto braking can be disabled permanently via the MBUX interface?

Also a word of advice - the way to get these companies to take your complaints seriously is filing complaints with NHTSA. You can do that here https://www-odi.nhtsa.dot.gov/VehicleComplaint/
Car manufacturers budget for a large number of consumer complaints and safety issues + settlements. But NHTSA reviews every single report and if a pattern is clear, they will start an investigation which can lead to recalls and fines.

Nissan is currently being investigated with this after NHTSA received 843 complaints: https://www.wsj.com/articles/feds-st...em-11568322336

Mercedes. Volvo. Nissan.. Is there any safe car anymore?

3tonks

Me too. I have a 2018 S560 4Matic and it happened to me last week going about 45 with no cars around me and no guardrails etc. Sunny day. On a previous day, it happened going about 30 on a 2 lane road, no guard rail, light rain. Very frightening on both occasions.

bayman123

New 2021 S560. Bought 3 days ago from a dealership with 45 miles on it. Was driving home from a restaurant with my wife going about 35 mph. Out of nowhere the car hit the brakes HARD; there was nothing in front of us. I was caught completely off guard. All I saw was a red triangle with an exclamation mark somewhere in the gauges before it recovered. There was a car right behind us that came VERY close to rear ending us.

I'm a mess right now. This is so dangerous. I just want to give this car back and never deal with Mercedes again. I don't know what to do next

(Googled sudden braking problem in Mercedes and found this thread)

achez

You can try to take it in for service and if you have a diligent service rep they may try to help you. Unfortunately what most have experienced is “operating as designed” and “cannot replicate the issue”. Since it doesn’t happen in every car, it seems to me that something is defective. If they would attempt to fix the issue by replacing sensors or something, I would be a lot more understanding. The next best thing is to continue to return the vehicle each time it happens to get relief under lemon laws and file a complaint with the NTSB.

JTK44

This has never happened to me in 18,000 miles on my 2019 E450.

I believe there is a sensitivity setting that you can adjust.

Have you tried doing this?

bayman123

It looks like brake assist has 3 sensitivity settings. The sounds and images I was seeing are consistent with what the manual describes brake assist will do. Mine is set to medium (factory default).

In this situation there wasn't a single car or object in sight in front of me. I'm not sure if turning down the sensitivity would help. I attached a picture of the road I was on. It happened just as I was driving under an overpass in the middle lane (it was dark). My theory was that the road ahead (incline) was perceived as a wall or something.

bayman123

Here is another picture of the overpass. It happened about where the red circle is... maybe 1 car length away from being under the overpass.

JTK44

Perhaps reducing the sensitivity will resolve your problem?

bayman123

The sensitivity setting should affect at what distance brake assist kicks in, not whether or not it detects false positives. Suddenly braking the car for no reason under normal driving conditions is a major hazard. Yes I could reduce sensitivity by one setting but that also makes the safety feature less effective. I feel like I shouldn't have to make that choice.

JTK44

Actually no.

The sensitivity affects both.

For example on my Ford Edge Sport, I was getting braking from pools of water. When I went to reduced sensitivity everything is fine including the emergency braking function.

If you take it into Mercedes the first thing they will do is reduce the sensitivity and return the car to you. Why not save yourself a trip, reduce the sensitivity setting and see if that solves your problem.

Just $.02 and your time.

evd22

It appears to be just another open stretch of road that AEB randomly deemed to be dangerous.

I assume you are in the US where you may be able to rely on lemon laws like others suggested to get rid of the car (I wish I could just based on the interior squeaks alone).

If that doesn't work, you can
1) try tweaking the software settings. Changing system sensitivity to "late" may help but not in my case: I disabled the active steering assist (and never used lane keep) and have been incident free for the two years since. Perhaps a certain combination of settings can also resolve the issues on yours.
2) turn off the aeb every time you start the car to prevent this happening again. I've come across some 3rd party solutions to keep this system off (via an adapter), but it is dodgy at best and I can't really find it now.

bayman123

Thanks for your thoughts @evd22 and @jtk44. Do you know if connecting an OBD-II device to the car will give me any more information about why the car behaved that way?

JTK44

Sorry, I do not know.

evd22

I don't know much about this either. But given the amount of complaints that we have here, and the fact that this remains a problem for so long, the system is probably functioning as normal.

AMGeneration

My E43 does the same, and they keep telling me the car is fine, we need to sue Mercedes for this fault

nhdoc

I was driving home from the MB Dealership in Fort Myers Florida with our "new to me" 2013 E350 station wagon which came equipped with the driver's assistance package. A beautiful "like new" car with only 47K miles on it. I sought out this car specifically because it had the Distronic adaptive cruise which I wanted because our Audi A6 has the same feature and I really like it. Anyway, at about halfway back on the 80 mile drive from the dealership and in perfect weather in a straight section of roadway with nobody in front of me the car suddenly sounds the warning beep and then applies the brakes rather aggressively. Needless to say I am upset to read that others have experienced this same problem and Mercedes is claiming "never heard of it" and that the system is operating as designed. When I asked the dealer the service manager first tried to say it was probably due to a dirty sensor...nope, the car was immaculately cleaned before I picked it up. Then he thought the car might have speed limit assist, but it does not.

Our Audi has never exhibited any such behavior in the three years I have been driving it so clearly it isn't "user error". At the end of this week we'll be heading back to New England and I will see if I can get it to replicate the issue again and try and figure out what causes it. Has anyone tried shutting off the various features one at a time to see if any combination of them is causing it? I really don't like the active lane assist and would sacrifice brake assist if I could just get distronic to work reliably. Has anyone shut all of those features off and tried to see if they can get distronic to work reliably alone?

JTK44

I too have turned off "lane assist": there are so many times, especially in New England, on two lane roads with broad shoulders, with trucks coming at you, that you drive to the right of the lane marking to give you extra room as that truck coming at you passes by. With lane assist on, as you go over the right lane marking the system alerts you and then slams on the brakes. Very scary.

Or if there is a vehicle parked on the right shoulder. State law requires you to move left: if you fail to put on your directional signal, as you move left the brakes may also be suddenly applied.

As I posted, there are settings for the emergency brake. Make sure yours is not at "normal" but at least intrusive.

nhdoc

Thanks, but in my settings menu I see no choices for sensitivity for the brake assist system, it's either on or off. It's possible that the sensitivity settings were added in later model years but mine is a 2013 and doesn't seem to have it.