Nib95

I know this conversation has had a lot of discussion and many people sharing similar woes, however, as the major threads on this subject end with people speaking of getting the latest transmission updates but never really following up, I just wondered, has anyone actually managed to rid themselves of the C43's Sport+ low speed jerkiness/aggressive back and forth movement? Whether through a new transmission, transmission software update, or anything else?

Don't get me wrong, I could live with the issue, but it's certainly far from ideal, and definitely makes you feel like a bit of a plonker at times. Almost like in Sport+ at low speed you're often fighting with the car.

I've tried adjusting my seat, stance and posture every sort of way, been super delicate with my throttle control, building up instead of poking the throttle in a low gear etc, but whilst I've managed to reduce the amount it happens, it still happens. I never had this issue in my previous vehicles.

The only way to stop the bobbing/jerkiness is to either manually switch up a gear, let off the gas altogether, or floor it in a linear smooth fashion. This makes me think it's an issue with the gearing set up, where the car has too much torque at a certain gear and rev range, between the point of the next and previous gear, where if it holds or you you're within, it causes aggressive vehicle interia and movement. I feel like this could theoretically be something Mercedes should be able software tune out.

So, has anyone actually managed to completely rid themselves of this issue? If so, how?

Cheers

sieglo

I pressed the button andtook mine out of Sport+.

Nib95

That's no fun..... Sport+ is what this car was made for. Those pops, crackles, gurgles and bangs... Plus the steering and drive all just feels much more responsive and agile.

Nib95

All the illuminated buttons need to be much brighter, especially the centre ones such as AC, radio, Nav, vents, media etc. Here's my XFS interior in comparison, just look at how bright the buttons can be made to be, and I don't even think this was at the brightest.

AMGiggity

There are already a few threads about transmission jerking like this one which I think has the most responses. Generally speaking it is a good idea to just respond to existing threads rather than starting new ones so other people with same problem can research the issue easier.

Nib95

The reason I've made this thread instead of simply posting in one of the others, is to try to specifically highlight and ascertain how many people, if any, have actually sorted out the issue, not necessarily faced them.

Having read through all the other threads, I don't actually know of anyone who's actually sorted the issue out yet, but if someone out there exists, hopefully their post will be easily visible in this very thread, instead of being buried in dozens of pages of another.

RichardCranium3

No one has “sorted it” because there’s nothing to sort on the cars end, short of changing the gearing. Your foot and the connection to your brain is the only reprogramming there is. End of story. Sorry, not sorry.

Nib95

So I reset my cars Transmission Adaptive learning, and sure enough the amount of jerking, though still apparent on rare occasion, no longer occurs nearly as often or as easily. This makes me think that somewhere the cars transmission learning contributed to the issue.

In any case, for those that haven't done this and are facing this issue, I highly recommend a Transmission Adaptive Learning reset.

Here's how to do it.
http://www.mercedesmedic.com/reset-mercedes-benz-transmission-procedure-instructions/


I've driven everything from 911's, M3's, M5's, S5's, S7's, RS5's, XFS's and more, and I didn't experience the same extent of bunny hopping in low gears the C43 gave me, if at all. Hell, my previous car I just sold was a Jaguar XFS, which never once had this same issue.

You imply this issue is solely down to user error or learning, but that is likely partly your own inexperience talking, because if you'd driven a wider variety of performance vehicles with automatic gearing, you'd realise this issue isn't as prominent in many other similar cars. Don't get me wrong, it can and does occur in other cars too (eg some of those without torque converters, or certain DCT vehicles etc), but it tends to occur less.

There is something specific to the C43's gearing, torque, throttle sensitivity, transmission and set up, that appears to exasperate the issue compared to many other performance vehicles. Some people may actually enjoy the way Mercedes has set things up, as it is more aggressive and demands more control or intention from the driver, but as a result it does at times also feel a tad less forgiving or less refined than other performance vehicle automatic transmissions.

I should clarify, I absolutely love my C43 and the joy and thrill it provides is consistently exhilarating, that said, I'm not going to excuse away this weird low gear jerking issue. At the same time though, it's something I can live with, especially following my Transmission Adaptive Learning reset, which seems to have greatly reduced the rate at which it occurs

Mr. J

Updated software for the on my GLC43 and it did improve the situation by reducing the frequency of the bucking and making it easier to recover from. It's still there, but now I can recover just by easing off throttle instead of needing to either go WOT or upshift. Prior to the update, the only way to recover from bucking was to come completely off the throttle (0% throttle), go 100% WOT, or upshift to 2nd.

I can't speak to the software update for the C43. I know that the drive maps are very similar between the GLC43 and the C43. The bucking problem does not happen with my C450. The C450 has the old 7G tranny which has a completely different set of quirks.

RichardCranium3

Classic case of correlation // causation. I stopped at the first mention of “I drove this...” then stopped. xthxbye

waisoserious

The 9G is not known for its smoothness. Lets just leave it at that. If you are trying to get the dealer to fix it, I would say save yourself the trouble because theres not much they can do to fix it. I dont know if your transmission is faulty and particularly jerky, but if its anything like the rest of ours, thats just how it is.

Even in Eco mode, I can feel stiff stutters (although a bit more cushioned) when it downshifts. So I can tell you that atleast from my own experience, the 9g is just not a very smooth transmission.

Mr. J

It's only this way in the '43 AMG applications. I've driven an E450 that was a totally different animal. Silky smooth in comparison, just not nearly as quick shifting. It held gears longer and released them much more smoothly. In the E63 the shifts are firm and not gentle, but the car will not buck like the C/GLC43s do.

It's all about the software mapping, there's nothing inherent in the mechanics of the tranny that make it behave this way.

There are a bunch of fanboys who insist that this fine, normal and perfect. It's not. It's just weird non-linear response to initial throttle input in S+. But even with it's quirks, the '43s are still a good platform to hoon and to DD.

waisoserious

The 9G is good at what it does. Its just not smooth.

Malar

Buy a different Car with a ZF Trans.

k9mosk

Sounds more like a torque converter issue than transmission. Wouldn't surprise me with such a low 1st gear.... seems like Mercedes went middle of the road selecting the size based on stall speeds and gear ratios.

Mr. J

Word! MB keeps building transmissions when they should just buy them from ZF. When was the last time anyone commented how much better a MB tranny was compared to a ZF? Answer...Never.

TModelle

I wouldn't say never. The last time was when Porsche upgraded their Tiptronic in the 996 from ZF to MB, that's when. It was a vast improvement.

RichardCranium3

This. Porsche PDK guts are licensed from MB.

ughc43

Disconnecting the battery to force a reset of the TCU seems to cure it for about a week or so for me (the instructions floating around to do the reset without a battery disconnect don't seem to have any effect with keyless go on the 2019 models), then it's gradually back to the same jerkiness.

Mr. J

I don't believe this is true. ZF helped Porche design the 7DT PDK which they also build.
https://en.wikipedia.org/wiki/Dual-clutch_transmission

Star4life

latest trans update on my 2017 c43 with 9g is fine is sports plus. can be finicky sometimes but not really anymore. i think i am used to how much throttle to apply now too. but get the trans updated if you havent. if you need someone to update it, I can do it. just pm me. or go to dealer and complain and ask them to update.

Nib95

Honestly I've just gotten used to it at this point. Is it ideal? Far from it. Does it still happen? Now and again. But like with so many things in life, once you're accustomed to it, it becomes much less of an issue. In-fact at times it can even be exciting or rewarding, as if you've learned to tame the beast or something lol.

Ultimately you just have to re-calibrate how you drive the vehicle at super slow speeds in Sport+, predominantly whilst coasting or gradually building speed from a stop. It doesn't really gel well with quick successive micro blips of the throttle at low speed. This is presumably because the throttle and transmission in Sport+ are hyper sensitive and not always particularly intelligent, thus get confused or stuck between Gear 1 and 2.

What I find is that when creeping out and building speed at very slow speeds in Sport+, eg in traffic or whilst at a roundabout etc, I need to do one of five things whilst driving in automatic, to prevent the twitchy transmission tantrums.

1. Rather than gently poking the throttle when creeping, hold it at a specific point and keep it there so the car switches gear before you need to apply more gas.

2. Either that, or apply and increase the throttle in a completely gradual and progressive way in one smooth motion.

3. Or rather than do either of the above, simply smash the throttle on your exit and floor it, that way the transmission will cycle through gears normally.

4. If the car does start getting twitchy and starts doing the jerky rodeo, use the paddle shift to manually shift up, and the jumpiness will stop.

5. Or instead simply let off the throttle altogether till it recomposes before re-applying gas.

6. This isn't really a point per se, but having the correct seating position, under thigh support or centre of gravity also really helps, since it stops your leg from having those annoying vibrations and movements that can set off the throttle and transmission jerkiness.


Other than that, I'm not sure any solution, software or transmission update exists that will get rid of the issue altogether. I guess it's just the way the transmission, gearing and torque etc has been designed. Hopefully it's something Mercedes can improve upon with the refresh.

waisoserious

In other words, if you want to drive slowly in S+ either:

1. Dont drive in S+ slowly

2. Drive slower

BayAreaAMG

I know this is about the C43 transmission, but thought I'd mention that my C450 does the exact same thing. Hard shifting mostly in low speed from 1st to 2nd upshifts, or 2nd to 1st downshifting. Does it often in comfort mode too.

Resetting transmission adaptive learning helped for about 9 days and with more time it became more rough. Just the nature of the beast I guess...