Minor clunk/jerk when taking off from a stop
Thread Starter
Junior Member
Joined: Sep 2021
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From: Orange County, CA
2012 C207 E550 RWD
Minor clunk/jerk when taking off from a stop
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.
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.
Last edited by RosSauce; Nov 28, 2021 at 05:35 AM.
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E400 W212
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.
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
Thread Starter
Junior Member
Joined: Sep 2021
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From: Orange County, CA
2012 C207 E550 RWD
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.
Last edited by RosSauce; Nov 28, 2021 at 03:45 PM.
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 68
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From: Orange County, CA
2012 C207 E550 RWD
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.
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.
Last edited by RosSauce; Dec 1, 2021 at 05:05 AM.
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1983 Nissan Shltbox
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.
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.
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 68
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From: Orange County, CA
2012 C207 E550 RWD
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.
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.
See the attached service bulletin (Ll27 .19-P-056898)
Schedule an appointment with your local dealer to have them ascertain if your issue is due to the 7G NAG2 transmissions activation/deactivation of the power-free or neutral state (KID) feature when in drive and stopped. If so, the bulletin calls for updating the transmission software and/or removing the driveshaft and greasing the splines.
I have a similar issue with my E250 BlueTEC 4Matic, only the jolt, jerk, lurch or bump occurs about 5 seconds after coming to a complete stop. The jolt is usually barely perceptible, but on occasion has felt like the car behind me has tapped my rear bumper. I only recently came across the bulletin, so have not had a chance to follow up.
Schedule an appointment with your local dealer to have them ascertain if your issue is due to the 7G NAG2 transmissions activation/deactivation of the power-free or neutral state (KID) feature when in drive and stopped. If so, the bulletin calls for updating the transmission software and/or removing the driveshaft and greasing the splines.
I have a similar issue with my E250 BlueTEC 4Matic, only the jolt, jerk, lurch or bump occurs about 5 seconds after coming to a complete stop. The jolt is usually barely perceptible, but on occasion has felt like the car behind me has tapped my rear bumper. I only recently came across the bulletin, so have not had a chance to follow up.
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!
Last edited by RosSauce; Dec 1, 2021 at 04:47 PM.
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2011 E550 Coupe
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.
Thread Starter
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Joined: Sep 2021
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From: Orange County, CA
2012 C207 E550 RWD
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?
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?
Last edited by RosSauce; Jan 6, 2022 at 06:48 PM.
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2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
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.
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.
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Mercedes Benz CLS 55 AMG
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.
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Mercedes Benz CLS 55 AMG
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?
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?
Junior Member
Joined: Mar 2019
Posts: 66
Likes: 10
Mercedes Benz CLS 55 AMG
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?
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?
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Posts: 66
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Mercedes Benz CLS 55 AMG
Believe it or not, this is a characteristic of the drivetrain KID or standstill decoupling function. It's NOT the hill or brake HOLD feature or an internal transmission issue. It bugged me when I first bought my E250 3 years ago (I, like you thought something was wrong) but I hardly notice it now.
You can either pay someone to disable to KID function or again, per TSB Ll27 .19-P-056898 pay to have your local dealer or shop remove and grease the driveshaft to eliminate or reduce the jerk/lurch you feel after you've come to a complete stop. The driveshaft is simply not sliding smoothly when standstill decoupling is activated and the drivetrain is unloaded. If you're having delayed engagement or jolting when taking off from a stop you may need to have the transmission software updated as well (or instead).
You can either pay someone to disable to KID function or again, per TSB Ll27 .19-P-056898 pay to have your local dealer or shop remove and grease the driveshaft to eliminate or reduce the jerk/lurch you feel after you've come to a complete stop. The driveshaft is simply not sliding smoothly when standstill decoupling is activated and the drivetrain is unloaded. If you're having delayed engagement or jolting when taking off from a stop you may need to have the transmission software updated as well (or instead).
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
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.
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Mercedes Benz CLS 55 AMG
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.
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Mercedes Benz CLS 55 AMG
Scott, I think you (or the dealer) may have skipped over a few other causes of the KID issue with your car. The TSB (being released in 2013) of course assumes a new or nearly new car. Did the dealer do anything else besides grease the driveshaft? How are your engine and transmission mounts (the car may have under 30Kmi, but it is over 10 years old now)? Was the engine and/or transmission software checked for updates and the adaptations reset? The fact that you can feel or notice a delay in the car going back into gear is sort of telling.
As I said, I hardly notice the KID activating on my car now. Of course, this is after updating the software, resetting the engine/transmission adaptations and servicing the transmission (fluid/filter change) over the course of my ownership. The pronounced bump/jolt when stopped in gear, is now just barely perceptible (to me).
The KID "feature" can be disabled, but this is not something a regular dealer tech would be allowed or able to do (and I can't see MBUSA having someone from engineering design/load modified coding on a car outside of warranty to disable a feature that is not exhibiting a critical or safety issue). As JettaRed said, you would need to find a remote programmer which would entail renting or building/purchasing a diagnostic system with the necessary software.
As I said, I hardly notice the KID activating on my car now. Of course, this is after updating the software, resetting the engine/transmission adaptations and servicing the transmission (fluid/filter change) over the course of my ownership. The pronounced bump/jolt when stopped in gear, is now just barely perceptible (to me).
The KID "feature" can be disabled, but this is not something a regular dealer tech would be allowed or able to do (and I can't see MBUSA having someone from engineering design/load modified coding on a car outside of warranty to disable a feature that is not exhibiting a critical or safety issue). As JettaRed said, you would need to find a remote programmer which would entail renting or building/purchasing a diagnostic system with the necessary software.
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.
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Mercedes Benz CLS 55 AMG
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?
Believe it or not, this is a characteristic of the drivetrain KID or standstill decoupling function. It's NOT the hill or brake HOLD feature or an internal transmission issue. It bugged me when I first bought my E250 3 years ago (I, like you thought something was wrong) but I hardly notice it now.
You can either pay someone to disable to KID function or again, per TSB Ll27 .19-P-056898 pay to have your local dealer or shop remove and grease the driveshaft to eliminate or reduce the jerk/lurch you feel after you've come to a complete stop. The driveshaft is simply not sliding smoothly when standstill decoupling is activated and the drivetrain is unloaded. If you're having delayed engagement or jolting when taking off from a stop you may need to have the transmission software updated as well (or instead).
You can either pay someone to disable to KID function or again, per TSB Ll27 .19-P-056898 pay to have your local dealer or shop remove and grease the driveshaft to eliminate or reduce the jerk/lurch you feel after you've come to a complete stop. The driveshaft is simply not sliding smoothly when standstill decoupling is activated and the drivetrain is unloaded. If you're having delayed engagement or jolting when taking off from a stop you may need to have the transmission software updated as well (or instead).
