S580 Brakes Failed
Our 2021 S580 brakes did not function and work as intended. Sitting in gridlock traffic the braking system failed causing impact with the truck in front of us. There was plenty of room to stop but NOTHING worked, No brake assist (noted by Mercedes Service department that brake assist will only work if the driver is not actively braking therefore the vehicle should have stopped) However, no alarms, no beeps, no emergency assist NOTHING and when the vehicle impacted the vehicle turned off and back on. Our vehicle is a safety nightmare and firmly believe that if we were going a high or normal rate of speed I would not be here to discuss.
Also have been notified from another Mercedes dealership that some vehicles are being sold with faulty computer chips as this was brought up based on said incident as asked if we had signed any paperwork at the time of purchase reflecting the same.
Question...
First has anyone had issues with the Driving Assistant System, Emergency Brake Assist, Brake Assist or Collision Notification?
Second, if the Mercedes as shown in the link
Thoughts?
Last edited by onebigfamily53; Feb 1, 2022 at 06:58 PM. Reason: Update
Also have been notified from another Mercedes dealership that some vehicles are being sold with faulty computer chips as this was brought up based on said incident as asked if we had signed any paperwork at the time of purchase reflecting the same.
Question...
First has anyone had issues with the Driving Assistant System, Emergency Brake Assist, Brake Assist or Collision Notification? I don't see autonomous vehicles gaining public acceptance for another decade.
Second, if the Mercedes as shown in the link https://www.youtube.com/watch?v=fajRI44z6Q4 is true then the question becomes how did our vehicle impact with another vehicle as the vehicle should have stopped without incident.
Thoughts?

The car should never drive 3/4 of the car length from the car ahead if driving on cruise command. Did the car alert or not etc.
Anyway, hope there are not many faulty computers or chips that are not being replaced, if any. Even if there were, I doubt a dealer would say so, more likely they would blame the driver doing something wrong.
On the other thread the car did not brake irrespectively of brakes being applied at full power. Does not seem to be the case in this thread, so two different accidents with the same car? This would be dangerous, the assist systems failing should not cause any accident, they are anyway only intended to evade from an accident that the driver or other cars cause. This car just has pretty ordinary ABS brakes with full manual operation where no computers are involved. How could this part fail?
Also have been notified from another Mercedes dealership that some vehicles are being sold with faulty computer chips as this was brought up based on said incident as asked if we had signed any paperwork at the time of purchase reflecting the same.
Question...
First has anyone had issues with the Driving Assistant System, Emergency Brake Assist, Brake Assist or Collision Notification?
Second, if the Mercedes as shown in the link https://www.youtube.com/watch?v=fajRI44z6Q4 is true then the question becomes how did our vehicle impact with another vehicle as the vehicle should have stopped without incident.
Thoughts?
Last edited by MBNUT1; Nov 25, 2021 at 06:05 PM.
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I don't know what to make of it. If there is actually a safety issue with OPs car, I hope Mercedes realizes it.
I also wonder if OP was relying too heavily on distronic and not paying attention to the road.




If however you relied on the assistance systems to stop the car for you, then I have to say you are doing it wrong. We are a long way from fully autonomous cars. Today's systems are level 2 and they are purely assistance systems. You as the driver are ultimately responsible and need to pay attention. Always be ready for those systems to fail. They are not infallible. They are there to assist you, but the moment you let down your guard, they may fail.
If he was using some kind of Drive Assist cruise control (not a great idea in gridlock traffic anyway), it still sounds like user error. In terms of an insurance claim, driver is still at fault. Not his car and not the person he hit.
If he was using some kind of Drive Assist cruise control (not a great idea in gridlock traffic anyway), it still sounds like user error. In terms of an insurance claim, driver is still at fault. Not his car and not the person he hit.
"Yes we were in a incident causing impact with the box truck in front of us. We were in gridlock traffic for about 45/50 minutes and were following the same car for about 15/20 minutes. The box van proceeded to go as we were approximate 3/4 of car length behind with plenty of room to stop but when I applied the brakes to stop the vehicle did not stop no matter how much pressure I applied. Also the vehicle did alarm sensing the truck in front of us. The brake assist did not work however have been told by Mercedes service department that brake assist will not engage if the driver is actively braking (which I was) It is intended for when the driver possible is not paying attention or falling asleep and not actively braking which makes complete sense however emergency brake assist is a whole different assistance. As I was actively braking without the vehicle stopping the vehicle emergency brake assist should have worked. It failed causing impact. The vehicle also turned off and back upon impact."
I agree with your statement about faulty chips however per another MB dealership we were asked by an employee if we signed anything upon purchase as to knowing there were faulty chips. I stated no then was told the MB in fact are selling vehicles with faulty chips but are requiring the selling dealership to have the new owners sign off that there may be issues.
Sorry to sound disagreeable but that is not the issue and that is not what the intelligent system is for.
The issue is that your brakes did not work "no matter how much pressure you applied."
The intelligent system is there to provide a back up for events that you don't brake for.
Lastly I fail to understand why the intelligent system would somehow magically be able to stop the car when you couldn't with all your might. It is activating the same hydraulic system that you are with the pedal. In the situation that you described you are the intelligent braking system. Clearly from your description there would have to be something more fundamentally wrong with the braking system than some electronic override. Which leads me to the next question. Did the brakes work after the event?
To add to your response of The intelligent system is there to provide a back up for events that you don't brake for. I agree as this is what was explained by MB but was told that the emergency stop assist should have engaged.
Last edited by onebigfamily53; Nov 27, 2021 at 03:48 PM. Reason: add to post response
I don't know what to make of it. If there is actually a safety issue with OPs car, I hope Mercedes realizes it. YES there is a major safety issue that is why I am afraid to ever get back into the vehicle. The brakes failed!
I also wonder if OP was relying too heavily on distronic and not paying attention to the road. NO I was not relying on the intelligent driving system, I keep asking if my brakes (the pedal) did not work when I applied pressure then why did the emergency brake assist engage or any alarms for that matter. Mercedes strives on safety and I agree but NOTHING WORKED! Having issues from day one is also a problem. The vehicle is a safety nightmare and I ask this of anyone no matter what vehicle you own, if your brakes do not engage when you are trying to stop then would you put yourself and/or family at risk for it to happen again or better yet at a high/normal rate of speed and possibly caused an horrific accident that you may not walk away from.







