miketc

Does your Distronic recognize a stationary object like a car stopped at a light in front of you? I use Distronic all the time and the one thing that worries me (a lot) is that the system does not detect a car stopped at a traffic light. I test it repeatedly and I swear I would slam the back of a stopped car if I don’t apply the brakes at the last second. I just wanted to see if this is a problem with my Distronic or is it the system’s imperfection. Let me know how your C reacts to a stopped car when Distronic is on.



Thanks much.

abstractls

its not designed for using on roads with lights, it may emergency brake but you will have an accident if you let it go

miketc

Let what go? I don't understand what you're trying to say in the above, could you explain.

A car could stopped dead on the highway/freeway/turnpike without lights too. Where did you find the info that Distronic is not design for roads with lights?

Thanks,

abstractls

Obviously talking about signal lights just to clarify. It is not designed to just drive for you completely, except in slower situations. In a high speed situation is a car slowed in front of you or braked to a complete stop it will work, but if you come up behind a car doing 65 mph and he is dead stopped its nto going to stop completely. It will kick in the emergency crash avoidance but it wasnt tracking the car. Essentially it needs to be tracking a car for it to work at that speed.

miketc

Not talking about emergency or highspeed situation. Driving toward a car stopped on the road rather it's for a light or stopped for whatever reason, the Distronic does not detect the car at all. If I don't brake, I think the car will not be detected until it's too late. I tested at various speed ranging from 30mph to 65mph, of course the higher speed tends to be hairier.

abstractls

I thought I was pretty clear in the explanation of how it works. The answer is NO however. Not in the situation you are discussing. The internets are not always the best for explaining well sorry

miketc

I found this in the owner's manual:

"Distronic Plus does not brake for obstacles or stationary vehicles." so this explains it.

I considered this as the short coming of this feature.

Critter

Just wondering, how many times did you try the stationary car test!!
Best just drive the car in "normal" mode and leave the electronics for the times when you are using a cell phone.
I can not believe you actually came on the site to ask, the dealership SA or MB should be able to give you comfort.

rediesel

Both of mine stop for stopped cars. I use it in stop and go traffic all the time. If I stop for more than 2 sec I have to hit the gas or pull the stick to get it going again. It does close in faster than I usually do and I'm spirited.

dave-t

The option I believe you are looking for is collision prevention assist with adaptive brakes which your car should have. At speeds above 5mph the systems radar-based technology alerts the driver if they are approaching a vehicle ahead at a speed and distance that suggests a collision is likely. It can also detect stationary objects when driving speeds up to 45mph. the adaptive brake assist automatically provides the ideal level of increased braking as soon as the driver steps on the brake pedal

miketc

It's not really a test but just noted the speed and distance when the computer does not detect the stopped car since I use the Distronic all the times. I just wanted to confirm if this is an issue with my car before contacting the dealer. Actually I find more informed people here than my dealer, just saying...

@rediesel, that's interesting since the manual says that it does not detect stationary objects like a stopped car.

@dave-t, I'm not looking at collision prevention assist with adaptive brakes; I'm looking for controlled slow down then stopped when Distronic is on, not emergency stop/braking.

Thanks all,

PeteInGilroy

This link at the 4:40 min mark shows how the car will stop if there is an obstacle in front of you.

abstractls

They have clearly said in many things I have read it will only come to a complete stop under a certain mile per hour but this is the collision assist. This will be an emergency type stop. The distronic will not react and slow down like it will in traffic. It is going to jam the brakes. I think they said under 40-45 mph is where it would come t full stop

abstractls

The optional safety systems that Mercedes-Benz now offers on the new C-Class include:

Distronic Plus with Steering Assist, a semi-autonomous assistant in stop-and-go traffic jams that operates at speeds below 37 mph, following the vehicle ahead even where lane markings are indistinct or lacking, providing a safe and easy means of following the flow of heavy traffic.
The BAS (Brake Assist System) Plus detects cross traffic and boosts braking if the driver fails to brake sufficiently. The PRE-SAFEŽ Brake system detects stationary vehicles as well as pedestrians, braking automatically if the driver fails to react, and prevents accidents up to 31 mph and lessens the severity of collisions up to 45 mph. In moving traffic, it assists according to the same mode of operation throughout the speed range between 4 and 124 mph.

trustoryson

This is exactly correct, and OP I completely get what you mean about people on this forum being generally more knowledgeable than the dealership.

In the case you mention, you are on a relatively open road with 500 feet between you and the next car which you eventually approach stopped at a red light. Distronic will not pick up on this if it was not "tracking" the vehicle previously; in that event it would be up to PRE-SAFE Braking to emergency stop you.

PeteInGilroy

I think I actually experienced part of the PRE-SAFE Braking today. I was coming up behind a car stopped at a red light and I guess I was going faster than the system thought appropriate. Just as I applied the brakes, I heard two loud beeps..I guess had I not braked, the car would have done so for me. Funny I didn't see any messages.

dave-t

I recant my previous post. Distritronic plus will stop the car if the car in front is at a complete stop. The only way your car will stop however is if the driver does not touch the brake pedal at all. As soon as you touch the brake pedal the distritronic will not stop the car due to human intervention. Keep in mind with all of the safety features if there is human intervention the system stops and let's the driver take over.