rmc76

Anyone else had auto collision detection bang the brakes on for an obstacle you know you are going round but your car doesn't?

Nearly every morning my car beeps and brakes if I'm not quick enough at a traffic island on the way to work. I have tried all angles and can only avoid it by going really really slow around it, much to the annoyance of everyone else!

C_Class_Dad

I've received the alert, but no brakes. Once, I applied the brakes myself. I hope it's working, just don't know how to test 😀

ManiacGT

Only happened once to me, when a car turned and stopped half way through the turn. Did exactly what it is supposed to.

LateC300

yup, this happend to me when i went around a motorcycle who was in the median turning left.

slammed on the brakes for a split second but i continued driving. scared the bejeezus out of me.

Xzer0

I hope mine works
it beeps, but it hasn't braked yet

I hope its not like the one on the BMW. Their collision assist thing will use its full brakes if a car got in front of you at the same speed as you. This will make the car suddenly brake in the middle of the highway which can get you rear ended. I was almost hit once and the car wasn't even mine.

I realized that when the collision assist beeps, the braking lights flash like three times.

Anybody know what the attention assist sounds like?

gfmohn

DISTRONIC PLUS does the opposite result from the same cause. Near my home is an intersection where cars must come to a stop. If I am letting the DISTRONIC PLUS slow my C300 behind a car ahead of me, the braking will suddenly release completely as the car ahead of me comes to a stop. It does so every time and only at this intersection. Even though the first few times I was not expecting it, I have always reacted quickly enough to avoid any close calls.

I finally figured out that the radar was picking up the curb of a small traffic island dividing the two lanes at the intersection. It is about a car length long, and the release of braking always occurs as the rear end of the car ahead comes even with the end of the traffic island. My radar is pointed more at the island at this point than at the car ahead, because the road approaches the cross street at an angle. Just before the intersection, it turns slightly to the right, in order to intersect the cross street at a 90 degree angle. It is the purpose of the traffic island to force cars to do this.

I tested my theory by angling my car to right of the car ahead of me as I approached the intersection. Then the radar did not pick up the traffic island, and DISTRONIC PLUS braked my car to a full stop normally.

Xzer0, I've had my C300 go to heavy braking when a car pulled into my lane ahead of me. This was quite a surprise to me, because I was bringing my new car home from accepting delivery at the dealer! The car ahead was going substantially faster than I was, so there was no chance of a collision. It wasn't full braking, but it would have been a problem if there had been a car behind me.

I have also had collision prevention slam on the brakes while passing a bicyclist riding on the shoulder. The road was straight and wide. It wasn't DISTRONIC PLUS, because the collision prevention sounded. Collision prevention has also slammed on the brakes while passing a jogger on the OPPOSITE side of the road! It was a medium-wide suburban road, and I was in the middle of a curve to the right, The collision prevention doesn't recognize the car is curving away from danger. It may "seen" that if I ci=ontinued in straigh line, I would intersect the path of the jogger. (In both cases, it was not full braking.)

In all cases the automatic features can be suspended by stepping on the gas, (Have you tried this, rmc76?) Stepping on the brakes also suspends DISTRONIC PLUS, but not collision prevention. Collision prevention will just make you brake even harder.

Xzer0

What's a traffic island? I don't think we have those here


I guess that you're the only one who actually saw Collision Assist in Action

XPS

They are raised cement between traffic lol

gfmohn

To whom are you replying, to rmc76 or to me? We both refer to a traffic island, and we both reported experiencing Collision Assist in action.

rmc76

Yeah traffic island is in the middle of the road , it allows pedestrians to cross at traffic lights . Effectively it creates a chicane you have to go round , confuses the car ib think ! I didn't know about the acceleration thing though, I will give that a try.

Lego

I had no idea it will brake by itself. It beeps pretty much everyday for me though.

rmc76

I guess if you get too close to the obstacle without taking any action then it applies the brakes. Still gives me a shock every time !

topsider

where is the sensor if your don't have distronic? i know with distronic, the sensor is in the star. I have two blank sensors in my side grills, those might be for PDC and are just still there if u don't have PDC for production cost reasons, same with in my rear diffuser.

cheerful

Now I know what those beeps are, or at least I think I know what they are.

So far is has not brake itself. Is that an option on the car?

Xzer0

I guess I was referring to both of you.

I think the dealership took out my Distronic radar to install the Illuminated Star. I remember that the car had it before they put on the star. Does the Distronic do anything to stop the car? Does it support the Collision Assist?

I wrote about the beeping somewhere in the forum a couple of months ago. I think it beeped when I was turning (at a curved road) and there were trucks on the side of the road or when it was raining. It usually beeps out of nowhere, so I end up looking around wondering what might have set it off. I might have faulty sensors

rmc76

I don't think the applying of the brake is an option as my car is pretty standard build. I guess it goes from lighting up the triangle if you are too close to beeping when you need to be alerted to approaching something head on. If you do not take any action from there it applies the brakes. When I hear beeping my reaction is to lift off which I guess the car interprets as not taking any action so it does it for me. A great safety feature if you don't read the situation in the road ahead but not if you are in control of the situation and just want to keep going.

HorshamRebel

Makes me glad I never went for the Driver Assist Package

jakc

Drive Assist Package is for auto cruise and active lane keeping. Collision Prevention is standard. At least on the My16s

HorshamRebel

OH
Thanks for the heads up

HorshamRebel

This sounds like a law suit just waiting to happen

rmc76

If it happens much more at that traffic island I will be claiming for flat spotted tyres!

C_Class_Dad

Same as MY2015

benzw205

How to know if we have the auto brake system installed ?

I know it's funny, but no time to check anything yet !

jolt8631

The Collision Protection System is fitted to ALL W205s, so no need to fret.

HorshamRebel

Mercedes Tweeted back to me when I said that this was happening...


Their response ?


If I'm worried take it to a dealer to check.




Nice to know they are "concerned", and are happy for us to spend more money with them while our cars are being checked.


Seriously though, this is definitely a call back concern if lots of cars have this.


Will be interesting to see how many out of all the 100,000s of the cars sold have this