epnfrn

I have a 2020 CPO S560 that I love in all ways but one - the god awful rough downshifts (especially 3 to 2). When I slow down, every shift is noticeable, and the 3-2 often feels like I'm stabbing the brakes, so bad in 'sport' that I don't use it anymore. I have read as many threads as I can on this problem, which appears to be common. I have an extended warranty and have taken it to the MB dealer twice. The first time they did a parked adaptation, which of course did nothing as forums have stated, but that's what they wanted to do. The 2nd time, I strongly encouraged doing the forced adaptations while being driven (as people have discussed on these forums). Rather than this, they assigned me the master tech who had been with MB for like 2 decades. He went for a drive with me for 20' and felt the rough shifts but basically said that this was normal for a Mercedes. Normal. I point blank asked him if the CEO of Mercedes was riding in this ultra smooth, luxurious car (smooth engine, smooth suspension, smooth leather, smooth everything except ... bang! downshift) s/he thought it would be 'normal'. I mean I have NEVER had a car that shifts this poorly, not even when I'm clumsy in my stick shift 911 is a shift this abrupt. No offense to the master tech, he was a nice guy and obviously very knowledgeable. I believe him when he says this is within spec, but just can't believe spec is acceptable to people.

He offered to continue to investigate this with corporate and is now saying there may be a software update coming mid summer. I of course am less than enthusiastic about another 4+ months of this with the hope that maybe an update is going to help me. Others have talked about doing forced adaptations while driving using Xentry. I do have Xentry and am willing to try this -- I PM'd another forum member who did this but have never heard back. Does anyone know the actual step by step procedure to do this? I asked BenzNinja and he wasn't positive. Thank you so much. And if you have a good procedure for fixing an annoying vibration/squeak in my driver's door trim, I'd love that too I've sprayed the crap out of with silicone spray without help. Ok, two complaints.

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Tom in Austin

What a PITA ... so many past posts and efforts to fix this! I never had it as bad as you, but I did the transmission service at 50k (instead of 60k) and my car's shifting actually improved some afterwards.

as.thompson

I had rough downshifts from D5 to D4. Had the dealer update the software and it improved markedly. Never had a rough D3 to D2; that was and still is smooth.

BenzNinja

iTrader: (4)

Maybe software downgrade would fix it if this is not normal I could get and put the original first software back in
normal or not normal... maybe worth comparing with a same model/year owner......

2012 merc amg

How many miles? As Tom Stated, I too did a trans service I believe it was around 58K miles and it really improved this problem although not totally. Maybe the dealer does some type of adaptation along with the trans service not really sure. The trans service was very expensive as I remember around 1200 or so.

epnfrn

21k, but present as early as when I got her at 18.5k. I’m 99.9% sure this is software based on other threads where they do rolling forced adaptations that result in buttery shifts. Just need help with the protocol. Ninja- if no one knows the protocol, I may take you up on backing the software up a version.

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S_W222

I had this same exact issue in my first W222 (though it was pre-facelift). Several owners had the same in the pre-facelift, but a few noticed it with the facelift. Downgrading the software, for my case, did nothing at all. The forced adaptation is the way to go. The link below shows the procedure that me and several other owners followed for their cars and most users here reported good results following forced adaptation. The protocol is described in post #64. My transmission was buttery smooth after the forced adaptation. Transmission reset, software updates, etc made no change whatsoever (works for a week or 2 but then it goes back to normal based on what almost most users reported). Forced adaptation was the only fix that had good results by majority of people (of course, there are outliers, always)
https://mbworld.org/forums/s-class-w...ml#post7961182

gumshoe100

I had the same issue. 2019 10k The dealer said there was a procedure to follow. First standing adaptation, the second step if that didn’t work was a valve body and that’s what they did on mine. They put a new valve body in and it seems to have taken care of the problem. The adaptation helped, but it didn’t eliminate it completely. I know exactly what you mean about that hard shift, it just comes out of nowhere and slams into gear and your passengers think you hit something no way is that normal

Tom in Austin

A new valve body? Must have been covered under warranty or would have cost a small fortune

epnfrn

Thanks everyone, and SW222 - it was certainly your thread that sounded most similar. I had read through it pretty carefully, but didn't notice the small print in that screen shot which described the protocol. I will absolutely try it! If this thing shifted smooth, it would absolutely make my day!

S_W222

If you have no hardware issues and parts that need to be replaced, then this should be the only solution that would work. If anyone else, or dealer or shop, try to make u pay for anything else, say goodbye to them and save ur money; all other resets or software fixed would only work temporarily.

epnfrn

As I PM’d S_W222, after messing with. Xentry for a couple hours, I was never able to find something that allowed me to do the adaptations. Anyone that has done this - do you happen to have tips or specific step by step instructions? S_W222 gave me some ideas, but anyone with specific instructions?

vinflouen

I have done this in xentry and it fixed my 3-2 rough slam shift on 2019 s560.
i also did trans service, including drain the torque converter, diffs, transfer case, at 48k.
the adaptation requires 2 people one to drive and one to enter values for shift points.
the other way to do it is a soft rest in xentry.
VGS, adaptations….and reset there.
ill open mine up if anyone has questions

epnfrn

Yes, I know I (and probably others) would love a step by step screenshot of the procedure. Clearly please only do this if you happen to be working in Xentry already and don’t mind a quick detour. Don’t go out of your way