Originally Posted by TModelle

I've read this thread thoroughly again and have figured it out. Here's a summary.

alexasa, RichardCranium3, stockbmw, jonathan358, zibby43, munis and AMGiggity are all on 2017/2018 9G-tronic transmissions that start in 2nd gear unless in Sport+, and they don't complain about jerking/bucking or rough starts in Eco/Comfort/Sport, and pay more attention to throttle application in Sport+ where it starts in 1st.

HotPotJ, evoi19, Candyman19, 3.Pointed.Czar and TModelle (me) are on 2019 9G-tronic transmissions that start in 1st gear in all modes from Comfort and up (no Eco mode) , and are all complaining about jerky starts and poor shifting even in Comfort mode.

The programming for 2017/2018 is clearly different than the 2019 models. It is no wonder that 2017/2018 owners can't agree with the points of view of the 2019 owners.

Originally Posted by HotPotJ

I didn’t select Parking or anything at the stop. My car is definitely behaving a little differently. I just test drove another new C43 coupe today and it was smooth as hell. Really have no clue why it’s like this now...

Originally Posted by stockbmw

Everyone will imply that's normal for c43. Do I like it no. Did I learn to live with it, yep.

Your car should jerk and buckle like mad bull in S+. In comfort, it does every now and then while slowing down on 2nd gear, just remove your foot from the brake should ease the jerking. The engine braking is terrible on this car, uses zero torque converter which is retarded.

Originally Posted by AMGiggity

What about the fact that OP says he test drove another 2019 and it was nothing like his?

Originally Posted by TModelle

Honestly, I don't know. I'm just pointing out that the 2019 models start in 1st gear and the 2017/2018 models start in 2nd, and what the owners are experiencing or describing may very well be different. That's all.

In my own experience with my 2019, I don't have any "bunny hopping" that has been described by others, but I find the 1st gear too short and pretty useless as it is such a "short lived" gear before 2nd comes along, seems really unnecessary to start in 1st. However, my 1st to 2nd gear shift isn't very smooth, not like a DCT kind of smooth, and I get the upshift fart no matter how light or heavy I drive the car. So the result is that moving off is overall pretty jerky for both driver and passenger.

Originally Posted by TModelle

Honestly, I don't know. I'm just pointing out that the 2019 models start in 1st gear and the 2017/2018 models start in 2nd, and what the owners are experiencing or describing may very well be different. That's all.

In my own experience with my 2019, I don't have any "bunny hopping" that has been described by others, but I find the 1st gear too short and pretty useless as it is such a "short lived" gear before 2nd comes along, seems really unnecessary to start in 1st. However, my 1st to 2nd gear shift isn't very smooth, not like a DCT kind of smooth, and I get the upshift fart no matter how light or heavy I drive the car. So the result is that moving off is overall pretty jerky for both driver and passenger.

Originally Posted by superswiss

FWIW, I've driven a C43 at the AMG Driving Academy. Granted it was on the track, but had to drive slowly in the pit lane with the car in S+. These are well run in specimens where the transmission has learned various driving styles. There was no discernible issue while slowly pulling away in the pit lane, or coming to a casual stop after the laps. The only negative impression I walked away with was that the stock brakes aren't up to the task. I have to say that the Mercedes transmission do an amazing job at learning one's driving style, but you have to be cooperative to some extent. One of the points our instructor made very early in the day is to use the proper driving mode for the situation at hand. For example he specifically said don't drive around town in S+. Use C and once you are on the highway or an open road then you can change to S+, but don't confuse the transmission algorithms by doodling around town in S+. Bad habits get learned by the transmission otherwise and the experience will be less than optimal.

I can share my experience with my C63S. Not exactly the same car, but the core of the transmission is the same. After I took delivery of it in Germany, it was definitely rough around the edges. Driving around town was jerky and not very pleasant. It's exaggerated in the C63S by the fact that it uses a clutch instead of a torque converter. For the next ~6000 miles I mostly did Autobahn and country road driving. Very little city driving. It learned well how I drive on the open road, but every time I got into the city it was still jerky. Then at around 6300 miles I dropped it off for shipping to the USA. Took possession of it again late September and have now driven an additional 2500 miles on my usual roads and taken it for some canyon runs on the weekend. At first it still had the same jerkiness around town, but here I'm doing more city-like driving and it clearly learned my city/town driving style over the last 2500 miles and has gotten fairly smooth now. There's still the inherent directness in the drivetrain from the fact that it uses a clutch, so if I mishandle the throttle it will be felt as a jolt in the drivetrain, but driven normally and skilled it's very smooth. My previous car with a dual clutch transmission learned to declutch in third gear when slowly coming to a stop. Pretty much how I do with manual transmission. The C63S still downshift all the way to 2nd gear, but it does it smoother now. Of course I have learned, too, and retrained my muscle memory so that's part of it. What it doesn't do anymore now is downshift all the way to 1st gear, unless I come to a full stop for about a second. I regularly pull away in 2nd gear now after brief stops. It does the same in manual mode. I can hold it in 2nd gear and pull away instead of going down all the way to 1st.

If I can impart one thing, use the proper driving mode for the situation and give the car enough time to learn how you drive. Don't confuse it by using S+ around town sometimes and C other times. I drive in C around town, and as soon as I hit the highway or an open road I put it in I*, which I've setup like S+, except with the suspension in comfort and the transmission in manual mode. I don't like the transmission shifting on me automatically on the highway. When I hit up a really fun road like the canyons I go to, then I put it in full S+. So really I think the important thing is let it learn properly in the right mode for the right situation. If you use S+ for spirited driving as well as driving around town, then it really doesn't know how you wanna drive in S+. You are teaching it two opposite ends of the spectrum that are not really compatible with each other.

Originally Posted by batman719

@superswiss going off of your post here, if a car has learned "bad" habits, is there a way to "reset" it so that it starts learning from scratch again? Or a way to otherwise "un-teach" the bad habits?

Originally Posted by batman719

@superswiss going off of your post here, if a car has learned "bad" habits, is there a way to "reset" it so that it starts learning from scratch again? Or a way to otherwise "un-teach" the bad habits?

Originally Posted by superswiss

Yes, the transmission adaptation can be reset. Not sure if this DIY procedure still works, but you can give it a try. Worst case the service department can perform the reset.

http://www.mercedesmedic.com/reset-m...-instructions/

Originally Posted by TModelle

I’m not sure why people are still perpetuating this transmission reset procedure for newer cars like we have. That web page clearly says it’s for earlier transmissions that are not 9G and also doesn’t mention cars with drive modes, it’s an outdated page. It talks about shift points adapting to the user. Perhaps in the past you have MB cars with one drive mode and the transmission shift points adapt somewhat, but if that is so then our 9G adaptation program must be quite dumb - the shift points never change or drift, they stay the same and are very predictable in each drive mode. I’ve tried many ways of resetting the transmission control unit in my 2019, but the shift points are always the same.

Originally Posted by superswiss

That's why I said, I'm not sure this specific procedure still applies. The thing is, modern transmissions factor many things into the decision when to shift. From throttle position to cornering forces, steering angles etc. there are a number of factors that determine the shift points. They are certainly not at defined rpms as if you hit up a canyon road with lots of turns it will hold gears longer for example even in C, or even in S+ the shifts happen at lower rpm and it eventually shifts into higher gears and keeps the rpm low if you drive sedated. There's still adaption taking place, too. I don't have specific experience with the C43, but I can tell you my C63S shifts different now than it did on day one. There are most likely differences between the 9TCT in the C43 and the 9MCT in the C63S, in particular because the startup-clutch in the MCT obviously wears in over time, so the clutch feel will change. My guess is that reseting the adaptation, while still possible, won't make that much of a difference as in the past, because the transmission algorithms use so many other factors and inputs to determine how to shift.

Originally Posted by zibby43

There is (supposedly; never tried it myself):

via https://mbworld.org/forums/c-class-w...ess-start.html