I have a 2012 E550 4Matic and I’ve noticed that about 50% of the time when accelerating after coming to a complete stop, there’s a very minor jerking or clunking feeling. It’s hard to describe, but kind of feels like the car is semi-roughly shifting into gear when ready to drive off or like the brakes get stuck then release abruptly. The other 50% of the time, the car smoothly takes off. I also noticed that when I release the brake after coming to a complete stop, the car sometimes doesn’t move until I give it gas while other times it starts to smoothly roll forward (this is of course without the brake hold activated and on a level surface).

Otherwise, all shifting, gear changes, etc. feels great. Never have this issue when stopping to change from reverse to drive and vice versa. This only happens when first driving away after a complete stop like at a traffic light while staying in drive the whole time. If I do a super brief stop like at an empty stop sign intersection, it’s also smooth and doesn’t ever jerk/clunk.

Motor and trans mounts are relatively new and I recently had the transmission service done which didn’t change anything. I don’t think the transmission adaptation was ever reset though. I also recently replaced the rear brakes/rotors and had a stuck parking brake shoe fixed. The front pads are meaty but rotors are worn. The car otherwise drives like a dream. It really doesn’t feel bad, but is ever so slightly annoying as it makes the car feel a little less smooth/refined/luxurious. I’m pretty stumped and was wondering if this is just a quirk of the 722.9 transmission or some other underlying problem.

I have a tuned 2015 E400 I acutally had similar problems when starting from a complete stop the car would feel slightly jerky if I just wanted to accelerate slowly.
I've learnt it was more the way I was pressing the accelerator.
If you only slightly press the pedal then let go it seems to have that jerk but if you press and hold or keep pressing it doesnt jerk.
Does it feel jerky if you step on it from stop ?

I'm not sure whether it has anything to do with this Look at the Don't #9 16:00 time stamp.

Appreciate the help! Unfortunately I don't think that's my issue since the jerk/clunk only happens right at the moment when I start to accelerate or can even happen when I simply release the brake pedal, before I hit the accelerator. It almost seems like the car puts on the parking brakes then abruptly releases it or it shifts itself into park then roughly puts itself into gear once the brake pedal is released. Now that I think about it, the clunking does sound very similar to the sound when releasing the parking brake.

Remove the parking brake shoes and test drive.

If need be...

It's not the parking brake. The dash light would flash. I'm clueless without more info.

Did some additional experimenting while out driving over the past few days. If I stop and hold the brake with only the minimal force necessary to prevent my car from moving forward, then it's pretty much always a smooth take-off. However, if I press a little harder on the brake and sit there for a few seconds and then take my foot off the brake/hit the gas pedal, I'll get the tiny jerk/lurch/clunk about 50-60% of the time right before or as the car starts moving. Sometimes it's just a minor clunk noise, other times it's a small jerk, and sometimes both. It just doesn't feel smooth and annoys me every time I stop at a light wondering if it'll be a smooth or minorly jerky take-off. Could it be an issue with the torque converter or something similar? Granted I'm pretty clueless on how the 7g transmission operates. The best way I can try to describe it is that it feels like something is kind of sticky/stuck and then jerks into place or abruptly releases which gets the car moving. It's puzzling since the car drives great otherwise.

My current thoughts are 1) transmission being a little clunky, 2) something with the rear parking brakes (but I can't see how this affects the car only when it's stopped while in drive), or 3) front brakes (also not sure how this would factor in exactly but while the pads are good, the rotors are worn/bumpy and I get a scratching noise when braking).

And weird, I didn't have any dash lights turn on when my right rear parking brake seized up. I only noticed it from a metallic burning smell and my rotor getting discolored.

Are you enabling the hold feature on the brakes, or is eco mode enabling?

I'd start here ^

Other than that, perhaps what the above member mentioned, possible "Brake Hold" malfunction? Sounds like you're able to affect/mitigate the malfunction with brake pedal manipulation. I'd still look into the TCM though. Always start with whatever work was last done.

...

Negative, I'm making sure I'm not activating the brake hold feature and I don't have the eco auto start stop on my 2012.

Sounds good, thanks!

Wow that sounds exactly like what I feel, I'll definitely get it checked out. I've never had to go in for a TSB before, do you usually have to pay for it or the diagnostic process?
Edit: after reading the service bulletin, the symptoms are exactly on point for what I'm experiencing. Just scheduled an appointment at my local MB dealership, thanks a ton!

I have this problem with my Jaguar XKR almost since it was new. Immediately after coming to a stop, you can feel a little jerk. This is a sticking "A "clutch in the ZF (German) 6HP26 transmission. No big deal, but it can cause a jerk if you accelerate while it is unsticking. There is an oil cocktail that ZF makes to minimize this but it won't hurt anything as long as the starting jerk doesn't get bad. The Mercedes may work differently but it sure sounds the same to me.

Just to provide a little update:

Finally got my car looked at. At first the Mercedes tech said they didn’t find anything wrong, but I was able to drive it with the dealership shop foreman who confirmed there is something weird going on. He thinks it’s related to the brakes/ABS pump/hill hold assist function. He showed me that my car does have the hill hold assist function which I had no idea about. It seems like it’s engaging even on flat surfaces. After stopping for more than a few seconds, I’ll release the brake and my car stays put. Then 1-2 seconds later my car does a little jerk/lurch forward like the brakes suddenly get released.

Anyone heard or experienced issues with this before?

Assuming the shop foreman is correct : He thinks it’s related to the brakes/ABS pump/hill hold assist function.
The sensors to look at would be the : yaw rate sensor and maybe the lateral acceleration sensor.
I think these 2 sensors are the ones informing the computer that the car is on a hill.

Xentry I believed can read this value in real time and hence it can be graphed during a test drive.
Assuming these 2 sensors are the bad boys, it could be as simple as a loose mounting screws.

Hill hold, sure, whatever. Did they fix it or not?????

If it's hill hold, a few keystrokes in Xentry should take care of it, like Prihadi said.

Did anyone find a fix to this? I have a 2014 CLS 550 that I just bought EXACT same issues with the brake and or transmission jerking at a stop light. Car only has 25k miles. I know this is an old thread but someone help me out here please if anyone has their ears on.

did you fix the issue? examt same symptoms here. I did a new valve body, conductor plate, and solenoids chasing this symptom and it didnt fix it.

any news? How did you fix?

...

WELL we did the drivesgaft grease and even took it apart a second time and Mercedes benz of S austin added super heavy duty grease. Issue still there,.I have definitely narrowed it down to KID as the issue. 3 seconds holding brake and it you feel it disable. I can even pull down "drive" lever and it engages it back into gear. Do you have any leads on whome can disable the KID? My tuner has no leads, Mercedes benz claims they cant disable it. Appreciate any help friend.

I always recommend @BenzNinja whenever there is a need to do any programming. I recommend you reach out to him and link this thread. While the dealer says they can't disable it, you should ask if there is a physical limitation, a policy restriction, or just lack of someone with programming skills. I doubt every dealership would have someone that knows and can use Vediamo.

...

Thanks! I direct messaged him.

I have replaced all the mounts, control arms , CV axles, new fluid and filter, new solenoids, new valve body, new conductor plate, new fluid and filter, new carrier bearing, new input shaft, and almost every god damn thing you can imagine man. Ive done my homework. Chased this to the ENDs of the earth.

I got my car back. They pulled input shaft out twice. Added a special grease that the head shop foreman recommended not even the one from the bulletin. It didnt fix it. We replaced input shaft and carrier bearing as well. The car to me is still not right. Does anyone know if the kid feature does not engageg in manual mode? Because my car is smooth in that mode. No feeling of disengagement or no jolt ever. Also, I think something may be wrong with torque converter. Because the car should not jolt and its going into a disengagement and not in slipping mode. The transmission is mixed up IMO. I find it hard to believe not even the best Mercedes mechanics in Austin Texas could figure this out. I replaced valve body prior. Conductor plate and solenoids with fluid and filter. It annoys the **** out of me to br frank and I still find it absurd. Im going to call MB corporate and file with them to see if anyone can fix my car. I also talked to ninja guy and it was wildly expensive and not sure he speaks English and communication was off. Is there anyone else that can tune out KID?