epasc

I am sure most everyone here agrees that 99.999% of "sudden acceleration" claims are due to driver error, but just in case, I thought I would pose this question.

My mother has a 2010 S600 (<2000 miles) and says that the following happened:

She was driving on the freeway at 70mph and all of a sudden, without prompting, the car quickly started to accelerate to 80mph and beyond. She was very alarmed and hit the brakes, which stopped the acceleration.

She says that she did not have distronic cruise control engaged and did nothing to cause this.

I assume that something happened with her accelerator foot or shoe, but she thinks not and is now scared to drive the car.

Is there anything that could cause this or are there any reports of bad accelerator communication on the S-class?

Since I am primary tech support rep for her, I want to give her a decisive answer. Thanks.

Diesel Benz

The accelerator pedal design and implementation has been the same for quite a long time and I have not seen any failure reports other than that the engine does not not gain RPM if the pedal sensor fails (even that is rare).

It has two sensors and if one fails and reports different data, acceleration is cancelled immediately.

The fact that applying brakes stopped acceleration, makes it sound like it would after all have been CC. Perhaps she used the CC lever accidentally instead of the blinker switch to resume previous speed setting or distronic was on after all and a car in front disappeared. The first option would be more likely, she should have remembered if she was following an other car.

emilner

I had it happen to me once. It was my fault, which I would argue is the case most of the time. I hit the signal to switch lanes and accidentally hit the distronic on without even knowing it (they are fairly close together). Needless to say the car started accelerating to the last speed I had it set to, which I immediately stopped by hitting the brake. I also sometimes mistakenly hit those damn buttons behind the wheel that manually shift the tranny, annoying to say the least.

Even though most people will insist they did nothing wrong, in the end the majority of drivers are distracted most of the time on the road and even the best drivers from time to time get distracted, even a guy like WSH....

RajwanyS550

just tell her the truth. U really bought a toyota camo. as a merc. LOL

JonMBZ

Yep this is very common complaint, she is hitting the cruise control. Most customers don't use it or know they have actually hit the cruise control. I actually did this on accident myself the first time I drove a benz, but I noticed it in the dash. It actually made me start using it lol.

Germancar1

Oh lord I knew it just a matter of time before this ridiculous nonsense hit the Mercedes community.

DRIVER ERROR 101.

The importance of knowing how a car like S600 works and how its controls function are priceless.

Go over the controls with her. See if you can duplicate the incident. I would bet you can't. Unless you or she did as others here have suggested, hitting the CC by mistake.

In the Toyotas the brakes did nothing, supposedly. If the brakes killed the acceleration it was the CC.

Now watch this thread attract some other owner who says the same thing happened to them, without hitting the CC.


M

cjf_moraga

It has never happened to me in my S600. Hitting the cruise control unintentionally and unaware does appear the most likely suspect I would agree.

Chris

Corsa9000

Well, it is a good thing she applied the brakes to disengage acceleration, so she is already ahead of most people who claim to have experienced unintended acceleration. Please also, remind her of the ability to switch to Neutral to disengage power to the wheels in case it happens again. There is no conventional gear selector on the center console in her car but she can still do it using the steering mounted gear selector.

As to validity unintended acceleration, I am sure it could happen in very rare occasions, highly improbable and unlikely, but just in case, a good driver should know how to neutralize it.

Anyway, glad your mother is OK and nothing bad happened.

epasc

Thanks. She is definitely fine, but still shaken and mistrusting of her car (however undeserved that is). I assured her that there is little that can happen in her 600 that cannot be overridden by the brakes, and that generally, "sudden acceleration" is due to some sort of driver intervention and not spontaneous.

(I was a skeptic even in the Audi 5000 era)

Thanks for all of the responses. I drive an S550 and am very confident in its safety and reliability. I serve as my mom's primary instructor on the nuances of her car.

I just wanted to ask the experts here if there was any reason to believe this could be something beyond a driver misstep.

patrick_y

This could be something beyond a driver misstep if there really was a problem. You may recall that Toyota just underwent a long recall regarding gas pedals causing unintended acceleration.

It is because of this, that all such cases need to be looked at seriously.

emilner

If a person is not very familiar with the car it can be VERY easy to grab the distronic lever instead of the turn signal, much more so if the wheel is turned at the time. I would not start a witch hunt here, if hitting the brakes immediately stopped the acceleration then it was distronic...

Diesel Benz

Even if it was a driver misstep, it should be looked at carefully. Assuming it was a hit to the CC stalk, it should not be that dangerous for a person who does not know how the CC works because one can only set the current speed accidentally. The resume function would not work unless the driver has previously activated CC. Of course if the driver makes a mistake twice, first at some higher speed, only then could the car accelerate from the CC stalk. An S600 would have distronic which prevents the car accelerating if another car ahead is driving slower. The surprise for the driver may make this inconvenient, if not dangerous.