JohnAJohnson

2014 E250 Bluetec, 4Matic, Driver Assist, Premium 1, Keyless-Go, built late March 2014. 2800 miles on it so far.

Driving at 55 mph in medium rain with cruise and lane keeping on, every Distronic Plus System (cruise, lane keeping, pre-brake, blind spot assist, etc.) went inoperative, displaying yellow warning messages one at a time in the speedometer display. The engine would respond to the accelerator and I sped back up to 55 and when safe, pulled over and powered down the car. Started everything back up and all systems worked fine. This was my first excursion in rain this heavy.

Anyone seen this one? Is there a way to easily pull the codes?

stale-bread

This happens to me in wet snow on the highway in my 2010. The sensors appear to overload and it seems to shut down until I either wipe the snow off, which works 100% of the time, and one time I just turned everything off, then restarted as you did and it returned to normal. So yes, this has happened to me, just assumed it was par for the course. I don't have an answer for your second question.

PeterUbers

Inoperative or inactive ... They mean two very different things ... Inactive means temporary and no need for service visit and inoperative means need to take the Benz for diagnosis

Sjorn

I have had the same problem. In heavy rain the system will basically turn off. Being that it probably can't accurately read or track the road and cars. I also have the E250 Bluetec with the distronic plus and steering assist. Snow does the same thing if the temps are right that it collects on the front bumper and areas to affect sensors. The system will go down for that - actually the first time I experienced and then started paying attention to the weather conditions when the system is down. Which is always in heavy precip (rain/snow), normal rain showers etc have not affected the system for me.

mikeyle

this is kinda related but i was driving once with no rain or rough weather and all my turn signals and brake lights were not working with the car telling me they were all inoperative. pulled over and restarted, everything was fixed...2012 e350

JohnAJohnson

Thanks for the replies all.

Live Oak

In the case of my car, it has happened out in the desert, no weather, no wind. I suspect a big grasshopper hitting the "radar port" area can do it.

DeanBee

In my experience (5 time Distronic failure) you don't need to pull over and restart the vehicle. It will reset itself after about 5 minutes while continuing your drive. Rain and fog have caused my failures.

GoBlando

It happens when the sensors get dirty. The manual specifies where the sensors are and tells you to clean them off when you get that message. I had it go out once in a wet light snow. Never again.

Also, if you ever have to get the windshield replaced make sure you get the real OEM windshield as the OEM equivalents tend not to work with the lane departure sensors. You need to call you insurance company to make sure they don't force you to use the oem equivalent. Progressive is apparently extremely aggressive and will only replace the windscreen with the cheap version.

ChuckinTucson

If you're driving in very heavy rain and/or snow, you probably should be using cruise control anyhow. Just a thought.

GregTR

From the manual:
Do not use DISTRONIC PLUS:
- in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
- on slippery road surfaces. Braking or
accelerating could cause the drive wheels
to lose traction and the vehicle could then
skid
- when there is poor visibility, e.g. due to fog,
heavy rain or snow

There is also the question whether the OP experienced "DISTRONIC PLUS Currently Unavailable" or "DISTRONIC PLUS Inoperative".

The system didn't "die" it just got disabled.

thefisch

I think every car manual has those same warnings for even basic cruise control.

JohnAJohnson

Not sure why it's so critical to understand the difference between inoperative and unavailable for the purposes of this thread, but since two of you have pointed it out, there must be something else I need to know. "Died" solicited exactly the feedback I sought, and since it "resurrected" itself either by me turning everything off or by the passage of time, to me, semantics didn't matter. But if I'm missing something, I'm all ears.

GregTR

One of those fault codes indicates the system disabled itself from use due to the sensors not getting adequate information resolution due to being dirty/rain/fog what-have-you. The other one indicates the system disabled itself due to one of the sensors malfunctioning and not working properly.

The former requires no user action, the system will re-enable itself and things will work once the obstruction/inclement weather has been cleared. The latter deems a visit to your MB dealer necessary.

dfordham

It's a radar based system; precipitation is highly reflective to radar. Heavy snow or rain will mask the desired radar reflections with "clutter". The system is smart enough to recognize this condition and deactivates the automatic function until the condition is eliminated.

Regards,
Don