Conrad Wo

Hi members. I purchased a 2015 S550 over a year ago. It does a hard downshift from 5th to 4th gear, especially when the car is cold. Then it goes away after about 20 min of driving. I have brought it into the dealer multiple times and the foreman tells me that they are fully aware of the issue, but they do not know how to fix it. Any experiences or advice ?

MJ50

moved to W222 forum...

S_W222

Ive addressed this problem and the fix for it in my post (see link below):
https://mbworld.org/forums/new-s-cla...ting-w222.html

Conrad Wo

Thank you

Conrad Wo

Brought my car in again for the 5-4 rough downshift. They kept the car for 2 weeks and informed me that they are unable to fix it and that a software is “in development for 1st or 2nd quarter of 2020.” I also called MBUSA and they were extremely unprofessional, first ignoring me and then telling me that they are not responsible to fix it once my CPO warranty runs out. I am never again buying a Benz. Any remedies? And I tried to show the service advisor the 1 successful fix on the thread and he didn’t want to hear it.

S_W222

I still can't get it why not all MB service departments can fix it. See the link below for the thread I started and I was able to successfully resolve the problem forever now. I was lucky enough to deal with one senior and smart service engineer who fixed it for me by 1st installing the latest software but also doing a ((""MANUAL") shifting normalization. The trick according to him is not to allow the software to just automatically chose the new shift points, but to "MANUALLY" adjust them while driving the car around and adjust them apart from values that the software has chosen based on his judgement on where they need to be to make shifting smoother for my case. it has been two months now and the car shift soooo smooth, can't even tell when it shifts up or down.

See my thread on this fix below:
https://mbworld.org/forums/s-class-w...ng-w222-2.html