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For what it's worth, I had the exact same experience while test driving the c43 coupe with the sales agent next to me. It happened about halfway through a 45 min test drive on pulling away from the kerb. In sports (or +) mode. I wasn't flooring the accelerator - just a gentle speed increase at which point the shuddering/rocking occurred. The agent couldn't explain it and it never happened again. I got the feeling something was awry with the transmission hunting through the gears somehow. Hopefully it resolves with use - don't some of these newer car transmissions "learn" your preferences over time?! Either that or a software update. Nevertheless the drive was so impressive that I have placed one on order!
This behavior is typical of a dual clutch or multi clutch transmission in which the transmission will disengage the clutch when it believe it will be coming to a stop. Therefore, when you are coming to a rolling stop or just slowing down to maybe 5 mph, it will disengage the clutch to save on fuel.
But when you start to accelerate again, the transmission has to reengage the clutch, giving it that jerky motion. You can learn more about it here:
Watch starting at 5:20. That part mentions the jerking while accelerating while braking, but watching the whole video gives you a better idea of MCT behavior. In general, I just assume it's going to happen and try to adjust how much I depress the accel pedal to avoid as much jerkiness as possible.
Yes there is good info in this clip but remember this is a MCT and not a dual clutch tranny.
It is a regular auto trans in construction and not a dual clutch design with 2 shafts.
the only basic difference is it replaces the fluid coupling with a wet multi plate clutch pack.
It will act much like the dual clutch is many situations like coming to a stop and both types will disengage and if you get back on the gas because the light turns green before you stop it sometimes jerks as it reengages.
It will only go into SAIL mode and coast in C mode to save fuel and you will see the sail boat icon on the dash and if you have a HUD the gear your in goes away.
Yes there is good info in this clip but remember this is a MCT and not a dual clutch tranny.
It is a regular auto trans in construction and not a dual clutch design with 2 shafts.
the only basic difference is it replaces the fluid coupling with a wet multi plate clutch pack.
It will act much like the dual clutch is many situations like coming to a stop and both types will disengage and if you get back on the gas because the light turns green before you stop it sometimes jerks as it reengages.
It will only go into SAIL mode and coast in C mode to save fuel and you will see the sail boat icon on the dash and if you have a HUD the gear your in goes away.
One thing to remember--this thread started out as a C43 transmission discussion and it does not have a MCT but a standard 9spd auto with fluid coupling.
Its problems are most likely all software related as are most of the MCT anomalies.
Finally getting around to going to the dealer to get my car checked out. As an added bonus, my check engine light came on today. Now there is a lurch when going from 1st to 2nd even in COMFORT mode!
Going this Friday and will update you guys afterward. Happy Thanksgiving!!
A reset will likely cure these issues. I used to have to reset it on my E550 regularly to get Sport to work. I am having no problems with my C43 in Eco, Comfort or Sport. It is rough in Sport+, but hey....
Hi all - I received my C43 coupe a few weeks ago, and generally it has been a pleasure to drive. I am, however, having one issue that seems to come up in S+. Sometimes when I am accelerating from a stop (even at normal/soft accelerations), the car starts rocking/jerking back and forth about 2-6 times like it is stuck and unable to switch gear. It also actually won't go forward more than a few feet when this is happening, even though my foot is on the accelerator. I take my foot off the accelerator and, once the rocking has stopped, reapply and it goes forward fine.
Similarly, when coming to a stop in S+, the car will jerk back and forth very noticeably/uncomfortably. It seems to be more than just a regular downshift. This happens when I slowly come to a stop over a longer distance. Can't remember if it happens when I come to an abrupt stop.
I'm not sure if this is normal, something I am doing wrong, or an issue with my car. This is my first sports car, so I haven't run into anything like this before. Would appreciate if anyone has any suggestions/advice. Thanks in advance!
Are you sure this is not "Throttle induced oscillation".
Your foot moves ever so slightly back and forth that is hardly noticeable, but it gets into a rhythm with the throttle and causes the bucking. It is most noticeable on turbo cars due to the boost surge!!! The way to fixed it is to move closer to the pedal giving your legs more of an angle in relation to the accelerator so when the car oscillates your legs do the moving instead of your foot.
Are you sure this is not "Throttle induced oscillation".
Your foot moves ever so slightly back and forth that is hardly noticeable, but it gets into a rhythm with the throttle and causes the bucking. It is most noticeable on turbo cars due to the boost surge!!! The way to fixed it is to move closer to the pedal giving your legs more of an angle in relation to the accelerator so when the car oscillates your legs do the moving instead of your foot.
I don't think that's the problem, but I should have a better idea either way soon. Just dropped my car off at the dealership this morning. Two days ago (long after the initial problem started) the check engine light came on. May be coincidental, but who knows. Now the lurching happens even in comfort mode....
I test drove two C43s--transmission in one seemed fine, the other had brutally hard kickdowns going 3-2-1 in Sport mode. Much rougher than any DCT or SMG car I've driven.
Think I'm going to sit out my purchase until people start getting answers on these transmission issues.
Are you sure this is not "Throttle induced oscillation".
Your foot moves ever so slightly back and forth that is hardly noticeable, but it gets into a rhythm with the throttle and causes the bucking. It is most noticeable on turbo cars due to the boost surge!!! The way to fixed it is to move closer to the pedal giving your legs more of an angle in relation to the accelerator so when the car oscillates your legs do the moving instead of your foot.
I believe this may be the case. It is very easily induced to the "oscillation" especially in Sport+ because of the high torque and tight gear ratios - designed to keep revs higher and reduce turbo lag. I am on day 3, and have managed to not do that today, though I can see it happening easily.
Looks like one of the wires connected to the control unit shorted in my car. Dealer replaced the wire/fuse and so far sport plus has been a lot better. One slight problem I had though - when I came to a stop in sport plus, I remained at 2nd gear the whole time at a red light. Then when I went to accelerate on green, there was a very strong jolt/lurch that caught me and my girlfriend by surprise. That was the only hiccup so far. Fingers crossed it was the last. Here is the full report:
The title of this thread is deceiving. Not at all what I through it was going to be about....
Haha ya.... was just trying to describe the motion that was happening when I would have difficulty shifting from 1 to 2 after slowing/accelerating after a stop. Curious - what did you think it would be about?
Is anyone still having this problem? Mine went away for a while, but this week the rocking came back and it is horrible. The transmission just does not like 1st gear. The car only starts out in 1st gear in Sport and Sport+. I drive in Sport+ 100% of the time.
The "rocking" feels like when you're driving a manual car and you release the clutch too quickly. When this happens in my C43, I either have to ease the gas slowly to get it to shift from 1st to 2nd (just like when easing off the clutch and onto the gas in a manual car) or I use the paddle shifter to upshift to 2nd gear quickly, to stop the "rocking".
Has anyone been to the dealer about this? What was the outcome?
Is anyone still having this problem? Mine went away for a while, but this week the rocking came back and it is horrible. The transmission just does not like 1st gear. The car only starts out in 1st gear in Sport and Sport+. I drive in Sport+ 100% of the time.
The "rocking" feels like when you're driving a manual car and you release the clutch too quickly. When this happens in my C43, I either have to ease the gas slowly to get it to shift from 1st to 2nd (just like when easing off the clutch and onto the gas in a manual car) or I use the paddle shifter to upshift to 2nd gear quickly, to stop the "rocking".
Has anyone been to the dealer about this? What was the outcome?
Yes, I'm back to having this same problem. If you check one of my prior comments in this thread, I did take the car to the dealer and they did make a fix. However, I think that was a problem separate from the jerking, as my check engine light came on the day before I was to take it in (for an appointment I had scheduled previously because of said jerking). That separate problem caused my car to be unable to get past 5th or 6th gear, but they fixed it by replacing the frayed wire.
I honestly think there is no fix for the jerking problem other than to adjust your driving. This is still pretty annoying though, as I always have to keep an eye on my acceleration whenever I'm at the shift point between 1 and 2, usually around 10mph. That means that basically any time I come to slow down for a red light that subsequently turns green or any other time where I'm slowing down and then accelerating right around that 10mph, I give it a 20-30% chance of jerking on me.
I would definitely keep hounding the dealer about this as this is not acceptable. I guess I am lucky as I don't have this issue with my car but I would definitely make the dealer accountable.
I still think it is driver induced. I had it happen at the beginning when I first took delivery.
If you accelerate rate in first gear after almost stopping it rocks the car. Everyone agrees this is when it occurs.
Your foot then starts rocking (realize it or not) and the effect becomes magnified. I have learned it is in fact me causing it and no longer have the issue since I adapted. It still happens to me - just less often.
The first gear is so tight / short on this 9-speed, it is more pronounced than most cars.
I am convinced there is is nothing wrong with the car.
I drive in Manual in Sport+ regularly and it doesn't happen because you wouldn't shift the same way as the automatic does. It is only in Manual.
It is not driver induced. It shouldn't be happening at all. Next time it happens try pressing the gas harder: the car bucks harder. Why? Because it is a transmission issue and the clutch and gear are not properly engaged.
Originally Posted by FastE
I still think it is driver induced. I had it happen at the beginning when I first took delivery.
If you accelerate rate in first gear after almost stopping it rocks the car. Everyone agrees this is when it occurs.
Your foot then starts rocking (realize it or not) and the effect becomes magnified. I have learned it is in fact me causing it and no longer have the issue since I adapted. It still happens to me - just less often.
The first gear is so tight / short on this 9-speed, it is more pronounced than most cars.
I am convinced there is is nothing wrong with the car.
I drive in Manual in Sport+ regularly and it doesn't happen because you wouldn't shift the same way as the automatic does. It is only in Manual.
I mentioned this problem in the AMG Private Lounge Community Forum and they asked that I contact my MB dealership and request them to open a service case (so-called "TIPS"). This will notify MB/AMG so can they can further investigate the issue.
Any 43 owner who has experienced this problem should have their local dealership open a TIPS service case.
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