Nice Ride

The S550 always had a bad jerk when slowing down through gears 5 to 4 to 3. Now randomly I will get a bad Bang into 4th with no heavy load, just pulling away from a stop light.
Anyone have any idea what would cause this..

I had the Dealer do the 40K Trans service a little early and no change.... Boy, am I glad I did not get the Renntech ECU tune....

Plutoe

Sounds like you have issues with the shifting solenoids located on the conductor plate This aint a DIY, get a good transmission scan or live with the issue which will get worse!

Nice Ride

Appt. with dealer set for Tuesday.... Still under B2B... Boy, am I glad I did not get the tune yet...

Manofsteelpt

My 2013 S63 was in the shop a few times and it was tuned. They never said anything about it. Not sure if I was lucky, or the issues I had didn't matter with the tune.

V222

Any resolution at the dealer? I have the same thing and I have taken it in twice. I am told they can't duplicate the problem.

Nice Ride

No problem found.... No codes in system. They said that they made some "Computer Adjustments" to the shifts. I will look for my paperwork and post the notes. How often does yours do it? Is it when slowing down, or just pulling away from a stop with no heavy load on engine...

V222

If you are in 5th gear and start going uphill, the downshift to 4th is extremely jarring, and totally out of character for a car of this type. The condition can be duplicated by downshifting with the paddles manually, but my dealer says there are no codes and they can't duplicate the problem. It's frustrating because otherwise I love the car. I currently have 12,000 miles.

it's good

Mine was doing the same thing.At 24k dealership did a quick test 541011,on-board power supply voltage maintain 540650,and program and code control unit 540991.All three also fall under another code of 561 WM67.It has been better since but can still be abrupt under cold and light load conditions.I believe the trans is the weakest system in an outstanding vehicle.Have driven or owned every generation since 1971 and think this is the best.Hope 9 speed is better.

Nice Ride

So far, smooth as silk on all shifts, up and down and all different speeds. I did not think they would actually fix the 5 to 4 that was always harsh... I will keep everyone posted. So far 1 day of driving, no, none, zilch... issues. I will give it a month in case they just did the basic Trans Reset......

Attached is the actual work order to possibly help others out with a similar problem.

jumpman726

For those of you that want to try a temporary fix you can reset the transmission yourself.

1) Get in your car and close the door
2) Push the Keyless Go button twice to turn the electronics on (DON'T start the engine)
3) Step on the gas pedal all the way to the floor and hold it there for 15 seconds
4) Push the Keyless Go button once
5) Take your foot off the gas pedal
6) Sit and wait 2 minutes (DON'T push any buttons in the car)
7) Open the door
8) Close the door and start your car as usual and you should feel a more responsive transmission when you drive

Radcad06

Thanks for this, Nice Ride. I've had the same issue on the 5 to 4 downshift. First fix by the dealer seemed okay for a while, now it's back to the harsh downshift. Unseemly for a car of this stature, for sure. I also had a large bang from the trans once, while accelerating at max velocity onto a freeway on-ramp. Love everything about this car except for these issues!

RJC

The 7G/722 trans has a reputation for harsh up/down shifts. The solenoids as mentioned by Plutoe may very well be the cause (even on a new '16). This requires dropping the pan and removing the megatronic unit, checking for excessive debris (metal filings) replacing the solenoids, driving adapting etc., etc.

FWIW,the new 9g trans is a tremendous improvement over the 7G...luv mine comp'd to the 7G in my '16.

Radcad06

Checking back in regarding this issue: I’ve had it in twice, the second time they performed the procedure mentioned and depicted by Nice Ride. Nope, still an issue. Going in for the third time and will mention the solenoid as a possible solution (I’m sure the service techs love hearing our ideas of what could be wrong).

For those who’ve had the dreaded “cannot duplicate customer issue” thrown back at them, I actually requested the service tech take a ride with me so that I could show him myself. He noted it was an obvious problem.

it's good

Sorry to hear your still having a problem.Truly hope you can find some resolution!In my last post on this thread I stated that I hoped the 9 speed would be better.I've been very fortunate to be able to lease a MY17 and am happy to report that the 9G is much better.Very smooth around town and cruising in E,ultra responsive and aggressive in S.Better shift quality,better coast down shifting,no clunking or searching.If you do get a bad shift the ECU records the next 5 shifts for diagnostics.Oh, and quicker.Also,MB won't tell you but I believe they have continued to tweak the suspension/ tire combo.The 17 is better over imperfections than the 15.In short,I'm in love all over again!

jumpman726

Just a side note for any potential S-class owners. The 7G transmission was used on 2014-16 models. The improved 9G transmission was introduced on the 2017 model.