Notices
S-Class (W222) 2014-2020

2015 550 Coupe rough downshift

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Jan 23, 2026 | 01:54 PM
  #1  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
2015 550 Coupe rough downshift

New to me 550 Coupe. No issues for a week of driving in Maryland, placed drive train in Sport for a few miles then back to Eco. Next day noticed rough downshift 4-3-2 when coasting to stop light, Light brake. No brake was even worse. Put back to Sport then to Eco...better for a while then rough again?? Intermittent not Constant
Reply
Old Jan 23, 2026 | 02:31 PM
  #2  
JohnLane's Avatar
MBWorld Fanatic!
10 Year Member
Community Builder
Community Influencer
Loved
 
Joined: Feb 2012
Posts: 2,627
Likes: 1,217
From: Phoenix
222 S-65
Seven speed transmission can be like that.
Reply
Old Jan 23, 2026 | 05:26 PM
  #3  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
At what point should I be concerned? Does system or ambient Temperature play a part?
Reply
Old Jan 23, 2026 | 06:14 PM
  #4  
as.thompson's Avatar
Super Member
Veteran: Air Force
15 Year Member
Liked
Community Favorite
 
Joined: Jul 2007
Posts: 743
Likes: 228
From: Santa Barbara, CA
S550C4, Porsche Cayenne
Originally Posted by Miwettig
New to me 550 Coupe. No issues for a week of driving in Maryland, placed drive train in Sport for a few miles then back to Eco. Next day noticed rough downshift 4-3-2 when coasting to stop light, Light brake. No brake was even worse. Put back to Sport then to Eco...better for a while then rough again?? Intermittent not Constant
Years ago I had a rough downshift 5 to 4 with my 2016 S550 Coupe. Dealer updated software (under warranty) and it is much better. I still get a slightly noticeable downshift occasionally when the trans is cold.
Reply
Old Jan 23, 2026 | 07:05 PM
  #5  
dmatre's Avatar
MBWorld Fanatic!
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 1,416
Likes: 340
From: Charlotte, NC
Had: 1987 300TD, Had: 2004 C230 Sport Sedan, Have: 2014 E350 Sport, Have: 2019 S450
Some can say it’s placebo effect, but most harsh downshifts stopped about the time I unplugged the oil pump solenoid. Do so at your own risk, but that is my observation
Reply
Old Jan 24, 2026 | 12:24 AM
  #6  
JohnLane's Avatar
MBWorld Fanatic!
10 Year Member
Community Builder
Community Influencer
Loved
 
Joined: Feb 2012
Posts: 2,627
Likes: 1,217
From: Phoenix
222 S-65
OP fresh transmission fluid is always good for them. First service due at 60,000 and every 30K thereafter. Begs the question.... why not every 30,000 to start with! Answer is obvious... attempt at keeping maintenance costs down while under warranty. They know it will happily live to 60K on original oil... but it will be overdue by then.
Reply
Old Jan 24, 2026 | 01:24 AM
  #7  
C280 Sport's Avatar
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2009
Posts: 3,830
Likes: 595
From: NY & FL
MB’s of all kinds.
How many miles ? Might be time for a transmission oil change. I do mine every 30k. It just makes sense. FCP Euro sells a kit with everything. These 7 speeds like that and it does them well.

Last edited by C280 Sport; Jan 24, 2026 at 01:26 AM.
Reply
Old Jan 24, 2026 | 10:30 AM
  #8  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
26000 miles. Very low for 2015. Lease I believe. Paint and interior are immaculate.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Jan 24, 2026 | 11:07 AM
  #9  
JohnLane's Avatar
MBWorld Fanatic!
10 Year Member
Community Builder
Community Influencer
Loved
 
Joined: Feb 2012
Posts: 2,627
Likes: 1,217
From: Phoenix
222 S-65
Originally Posted by Miwettig
26000 miles. Very low for 2015. Lease I believe. Paint and interior are immaculate.
Ten year old fluid is ready to be renewed.

Benz Ninja can flash software that changes how the transmission behaves. For the better. Among other things. Oh look! His banner ad is at the top of the page.
Reply
Old Jan 24, 2026 | 07:20 PM
  #10  
Mitch Alsup's Avatar
MBWorld Fanatic!
10 Year Member
Top Answer: 1
 
Joined: Sep 2014
Posts: 1,173
Likes: 431
S600
And people wonder why I still prefer manual transmissions.....
Reply
Old Jan 25, 2026 | 11:29 AM
  #11  
JohnLane's Avatar
MBWorld Fanatic!
10 Year Member
Community Builder
Community Influencer
Loved
 
Joined: Feb 2012
Posts: 2,627
Likes: 1,217
From: Phoenix
222 S-65
Originally Posted by Mitch Alsup
And people wonder why I still prefer manual transmissions.....
I don’t wonder. Mercedes didn’t picture old savages like us rowing our own in our cars with 1000+ NM of torque.
Reply
Old Jan 25, 2026 | 02:08 PM
  #12  
red996's Avatar
Member
5 Year Member
Liked
 
Joined: Mar 2020
Posts: 92
Likes: 43
2013 W221 S550 2016 C217 S550
OP. Do you have service records? Was your transmission fluid ever changed? Need to use the right fluid too. Change it? Needs to be done probably? Also, check for oil leaks at the front of the engine.Not transmission related, just m278..... stuff

Last edited by red996; Jan 25, 2026 at 02:11 PM.
Reply
Old Feb 19, 2026 | 05:39 PM
  #13  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
Took my baby in today, shop said there was a recall on the exact problem I described, rough shift from 5th to 4th. Checked software and update had been performed. They are changing fluid and filter and (reseting software)?
Stay Tuned
Reply
Old Feb 19, 2026 | 07:45 PM
  #14  
JohnLane's Avatar
MBWorld Fanatic!
10 Year Member
Community Builder
Community Influencer
Loved
 
Joined: Feb 2012
Posts: 2,627
Likes: 1,217
From: Phoenix
222 S-65
Get Peter to give it ‘additional modes.’ Smoothed out shifts in C and sport for mine. S+ is a bit much. M just for my own amusement.
Reply
Old Feb 19, 2026 | 10:57 PM
  #15  
as.thompson's Avatar
Super Member
Veteran: Air Force
15 Year Member
Liked
Community Favorite
 
Joined: Jul 2007
Posts: 743
Likes: 228
From: Santa Barbara, CA
S550C4, Porsche Cayenne
Originally Posted by Miwettig
Took my baby in today, shop said there was a recall on the exact problem I described, rough shift from 5th to 4th. Checked software and update had been performed. They are changing fluid and filter and (reseting software)?
Stay Tuned
Doo you have any identifying info about the recall - name or number? - that we could reference with our dealers?
Reply
Old Feb 19, 2026 | 10:59 PM
  #16  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
I'll ask tomorrow when I pick it up
Reply
Old Feb 20, 2026 | 12:50 PM
  #17  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
I haven't picked the car up yet, service manager emailed this to me.
Bulletin provided to me by Autowerkes Belair Maryland
https://static.nhtsa.gov/odi/tsbs/20...76661-9999.pdf
Reply
Old Feb 20, 2026 | 09:10 PM
  #18  
as.thompson's Avatar
Super Member
Veteran: Air Force
15 Year Member
Liked
Community Favorite
 
Joined: Jul 2007
Posts: 743
Likes: 228
From: Santa Barbara, CA
S550C4, Porsche Cayenne
Originally Posted by Miwettig
I haven't picked the car up yet, service manager emailed this to me.
Bulletin provided to me by Autowerkes Belair Maryland
https://static.nhtsa.gov/odi/tsbs/20...76661-9999.pdf
Many thanks!
Reply
Old Feb 21, 2026 | 08:36 AM
  #19  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
Picked up the car this morning, it's 40° here in Maryland and the rough downshift is still there. They did a full transmission service, new fluid, filter, etc. $1000 Went back to the shop and talked with the service manager, he said it could take a couple hundred miles for the updates and new adaptations to fully take affect. On the plus side, it updated the Comand center with new graphics, and the pneumatic seat functions have returned.

Last edited by Miwettig; Feb 21, 2026 at 08:38 AM.
Reply
Old Feb 21, 2026 | 11:35 PM
  #20  
BenzFan2001's Avatar
Junior Member
 
Joined: Aug 2021
Posts: 41
Likes: 15
CLS550
I’m interested in the new graphics, could you post a photo of them
Reply
Old Feb 25, 2026 | 03:01 AM
  #21  
badq45t's Avatar
Super Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2019
Posts: 573
Likes: 179
From: Half Moon Bay, CA
2016 S550e, 2005 Nissan Xterra 4x4, 1984 300ZX
Really new graphics? I had same issues and software update and followed by the tanny service got much better but still has some issue I have just learnd to live with it. Before that while under CPO warranty I literaly though someone had rear ended me it was so brutal, it got way better but still not as smooth as I would like.
Reply
Old Feb 25, 2026 | 07:35 AM
  #22  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
My Bad... The graphics haven't changed. I believe when I picked it up and was the first to start it after the update… I guess… There was a spinning globe in the command display that I never saw before, but I have not seen it again.

Rough downshift is still there when temp is below 45°. Service manager said to give it a couple hundred miles for the system to learn the new updates. Something else I noticed that I didn't notice before is that it skip shifts when breaking. 6–4–2. It may have done it before but I didn't notice because I wasn't looking at the display.

Last edited by Miwettig; Feb 25, 2026 at 07:54 AM.
Reply
Old Feb 25, 2026 | 08:11 AM
  #23  
C280 Sport's Avatar
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jan 2009
Posts: 3,830
Likes: 595
From: NY & FL
MB’s of all kinds.
Just curious did they check the transmission solenoids? I know people have changed those out of the 7 speed and that cured it.
Reply
Old Feb 25, 2026 | 09:43 AM
  #24  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
Did not replace solenoids. Are they external to the transmission or does it have to be drained to access them?


Last edited by Miwettig; Feb 25, 2026 at 09:44 AM.
Reply
Old Feb 25, 2026 | 11:03 AM
  #25  
Miwettig's Avatar
Thread Starter
Junior Member
 
Joined: May 2023
Posts: 40
Likes: 2
From: Maryland
2015 S550 Coupe
Now it’s rough from 4-3

is this damaging the transmission?

Last edited by Miwettig; Feb 25, 2026 at 11:07 AM.
Reply


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 04:30 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE