rabend

I have a 2014 ML350 Blutec with Distronic. As best I can tell, it will not slow down or stop if a stationary vehicle is in front of me. If there is a moving vehicle in front of me slowing down to a stop, my vehicle will do the same, but if I approach a stopped vehicle at a light, my vehicle does not seem to slow down and I can't handle the pucker factor to find out. Can anyone expand on what the vehicle actually does?


Thanks

GregGebhardt

My 2014 ML350BT will stop at moving and stationary objects.

First a audible alarm and then braking, serious braking.

On several occasions I have not braked for vehicles in front of me that are turning off the road. I am anticipating they will be done with their turn and do not apply brake. My ML does not like this and will alarm and apply brakes. On several other occasions I have had my attention diverted only to hear the alarm when the vehicle in front of my stops suddenly.

I do not have the trust to throw my new ML at another vehicle or stationary object to see it will stop first. I do consider the system to be " an additional pair of eyes" while driving.

I did turn OFF the lane deviation part as it would activate too often in city driving. Maybe long highway work it would be activated again.

rabend

If a vehicle in front of me is moving, even slowly, my vehicle will follow its speed to a stop as in a turning vehicle or one coming to a stop. It does not appear to do anything if I approach another vehicle that is stopped and was never moving within the distronic radar. I should have been more clear in my question. The other thing that caused me to ask the question was the following excerpt from the owners manual:

Important safety notes

WARNING
DISTRONIC PLUS does not react to:
people or animals
stationary obstacles on the road, e.g.
stopped or parked vehicles
oncoming and crossing traffic

GregGebhardt

The times my Distronic has activated were for vehicles either turn off the road in from of me or a vehicle that braked I front of me.

The brakes go full and hard and are in the non skid mode. It is almost a buzzing sound as the brakes pulse on and off many times a second.

gplank

I have it Distronic on my MY13 ML and so far I've only experienced the beeping when somebody on the highway suddenly moved in from of me and slowed down. But I think I was then quick to step on the breaks myself before it took over.

I thought the system paid attention to stationary objects, and this is what the literature I have says.

It might be that while DISTRONIC PLUS does not react to stationary objects, it may be another system, like COLLISION PREVENTION ASSIST, that does this.

See this COLLISION PREVENTION ASSISTvideo produced by Mercedes:


Look for the 32 second mark in the video for when the voice-over mentions that the system can even detect stationary objects.

Also, see page 6 of this Mercedes technology guide, attached, where it mentions stationary vehicles if you happen to drift out of your lane:

"As of model series 207/212 MOPF and 222, the system
also performs a course-correcting, single-sided brake system
intervention with non-continuous lane markings if there is
a risk of collision with vehicles on the adjacent lane due to
oncoming traffic, vehicles overtaking rapidly, parallel traffic
or stationary vehicles."

Apparently it also matters which model of the system you have.

I would take you vehicle into the dealer and have them check it out. Maybe there is something wrong with your system.

Or maybe there was interference with another radar system (from page 11 in the attached):

"In addition, the DTR+ system can shut off in the vicinity of radio
astronomy facilities. Manual deactivation may sometimes
be necessary here (code 233 only). Similar radar technology
in use by other road users or e.g. toll systems, automatic
door systems, can also cause the system to shut off."

Speed can also be a factor (page 46):

"The COLLISION PREVENTION ASSIST PLUS system can perform
autonomous partial braking at vehicle speed ranges of
7 - 200 km/h for moving and stopping objects and 7 - 30
km/h for stationary objects."

rabend

Thanks! Excellent references. It seems a little complicated with some features only working within specified speed ranges. I think I am going to play it safe and assume no recognition of stationary objects.


Regards,

340z

I don't blame you for not wanting to find out just how 'well' these systems work. I have had the alarm go off when approaching a stopped car at a light, and I was easily able to stop the car. However, i was already slowing. Distronic was enabled, but not engaged.

I've also experienced the ML coming to a complete stop when Distronic was engaged in what turned into stop and go rush hour traffic. This was a bit unnerving at first, and my foot was hovering over the brake and ready to pounce. It actually worked for a good 5 miles, with a lot of complete stop and go. At that point, I instinctively hit the brakes when traffic bunched up, and this unengaged Distronic.

As to whether or not the car will come to a complete stop with out Distronic engaged, I found this from the IIHS.org site. They've added a collision avoidance test.

With just Collision Avoidance, the ML only scored 1 out of six points. However, with Distronic, it moved up to 5 our of 6. Note that it did not come to a complete stop in the 12 or 25 mile tests. Rather the car slowed by 11 mph and 14 mph, respectively. (fyi - the new E's score a 6, because they are able to completely stop)

***************************

Applies to 2013-15 models

System details

• Optional Pre-Safe Brake
• Optional Distronic Plus

Package name

• Optional Driver Assistance Package

Overall evaluation


Superior
with optional
equipment
5 points total


Forward collision warning

This system meets the National Highway Traffic Safety Administration's criteria for forward collision warning.
1 point
Low-speed autobrake

In the 12 mph IIHS test, impact speed was reduced by 11 mph. 2 points
High-speed autobrake

In the 25 mph IIHS test, impact speed was reduced by 14 mph. 2 points
Tested vehicle

2014 Mercedes-Benz ML 350 4-door 4wd

********************************

dawizard

I didn't realize I didn't have Distronic on my car when I bought it, I assumed it was part of the Driver's package

I don't have a big remorse about it, I think I would use it mostly when going on long drives but how useful do you find it during your regular commute? Does it often get in the way and you find yourself turning it off or the other way around? I think MB definitely gives a lot of peace of mind in terms of safety features, I was hoping Distronic would be a standard feature in these (maybe in 2015?)

340z

If you have the Driver's Assistance Package, then you do have Distronic.

The Driver' Assistance Package is $2800 and includes:
DISTRONIC PLUS with PRE-SAFE Brake
PRE-SAFE Brake
Active Blind Spot Assist
Active Lane Keeping Assist

Distronic, Active Blind Spot and Active Lane Keeping can each be enabled from the steering wheel controls. So you could have them, but just not have then enabled.

There is another package - Lane Tracking Package that includes a lesser subset:
Blind Spot Assist
Lane Keeping Assist
Neither of these are "active" (i.e. they will warn you with a beep and lights if someone is in your blind spot or you are crossing a lane line, but they won't activate the opposite side brakes to pull you back into your lane, like the "active" versions can)

I leave all of them on and in 'active' mode. As for functionality, I wouldn't another car without blindspot assistant, and I like the 'active' function.

The lane keeping assistant is of lesser value, and frankly, the 'active' version is sometimes a pain. For example, if you are exiting the freeway, the smoothest driving line is often slightly outside of the white painted lines. If I don't still have the turn signal on at the point I'm about the cross the line, the car will brake. Also, I once was driving on a curving mountain road and moved right to let some motorcyclists pass me. It was when I first got the ML, and I had not kept the turn signal on, so the ML braked on the left side and started to pull me back into the center of the road. I'm sure the cyclists thought I was an idiot, but no one was hurt or close to any safety issue.

As for the Distronic Adaptive Cruise, I rarely use it, except on very long freeway road trips. The stop and go traffic experience that I described above was the first time I'd tried/experienced that particular stop/go traffic with Distronic scenario after a year of ownership. I do think that Distronic is the best cruise control that I've ever experienced, because of the 'adaptive' function. This feature makes cruise control a viable option in roads with other cars. I never used basic cruise control, because you were always braking and having to reset it in normal freeway driving. One downside to Distronic (and all cruise controls) is that they tend to have more 'lead' foot acceleration than my driving style, so mileage with cruise on in traffic or hills is lower than I normally get with my foot controlling my speed.

Dave

GregGebhardt

I use all the features of the Driver's Assistance Package except the active lane keeping assist. Like you it would apply brakes when you did not need them because you are crossing a line.

I might reactivate it on a long trip on the highway but it is not good around town.

dawizard

Thanks for the details, Dave. I stand corrected, I have the Lane Tracking package and Parking assist package, not the Driver assist package so except for the Parking, others are "assist", not "active".

I am getting used to the Lane assist and blindspot assist, can't imagine having to drive without that now, so useful and re-assuring specially when maneuvering on somewhat busy roads.