MBS430

I have 08 S550 (W221) and been experiencing rough shift at cold start.
by "cold start", I mean = vehicle moves off for the first time after being parked overnight.

approx 6 month ago, the dealer installed a new valve body (2202702706)
then problem came back.
Updating transmission & motor software did not solve the issue.

Then, the shop foreman determined that I have an INCORRECT valve body.
WHOA!?!?!, I was like wtf!?!? They themselves installed the alleged incorrect valve body .... Anyway, I decided to not pursue why , I focused more on lets get the RIGHT one now)

Now I have a newer valve body 220270320688

so based on:
DTB S-B-27.19/118a JUN10 – MY-All, Transmission 722.9 in Models 164, 171, 203, 204, 207, 209, 211, 212, 215, 216, 219, 220, 221, 230, 251, 463 ordering notes for Electrohydraulic Control Unit

Control unit 2202701406
replaced by 2202701306 then
replaced by 2202702706 then again
replaced by 2202703206-88

let's see if this is THE one now ....

IDriveAnM5

Sorry to hear about your situation. It might be a little while before the cold weather is back for you to test it out.

MBS430

thanks M5!

just to clarify "cold start" = I meant, the first gear shift after ~ 6 hr of being parked. Usually in the morning after being parked overnight.
I don't think the issue is temperature related. I would speculate it was more due to ~6 hr being parked and the ATF is "somehow leaked" from the transmission's plate pressure

here is copy paste from service bulletin:
LI27.00-P-048552
Complaint: after a cold start, slippage may occur in in the 2-3 shift when vehicle moves off for the first time
Cause:
Basic charge for the K1 piston is not guaranteed with a cold start. The plate pressure still has to be built up. This can cause the shift operation to be slip once.
Remedy:
Topis is known. A software improvement is being produces.

IDriveAnM5

Ok, I see. Seems like this sort of thing should be absent from these cars. But I guess that can be said for many things. Good luck man.

dannieboiz

I thought this was a problem with the 07's only?

Lenn777

Should I be worried about the same issue?

MBS430

my issue is having rough shift when the vehicle moves off for the first time after being parked overnight. It is so rough that the car actually jolts.

does yours shift smoothly after being parked overnight?

nyca

I have a 7G transmission in a W204 C Class - it did this from new, the first cold 2-3 shift holds the engine RPMs a little higher before engaging. After that, it doesn't occur again. Don't waste your time/money trying to get it fixed, unless the jolt is violent and severe. I have 60K miles now and the transmission is running fine even in the presence of this anomaly. You shouldn't be accelerating hard during the first 50 feet driving off on a cold engine anyway, a gentle pull away lessens the "jolt" of this first shift.

Lenn777

I'm not having any problems with rough shifts when I go to work. That being said, will I have issues when the weather starts getting cold?

jctevere

Has the remedy been resolved yet? I haven't had time to get into my dealership. This issue is present in my 2009 c300 4matic w204... It started around 30k miles or so, and now at 41k miles, I would say it has gotten progressively worse and is much more noticeable and annoying.

ts350z

I just replaced my conductor plate inside the valve body. Spent about $1500 at the Mercedes dealership. I've got my car back for about one month..., still drive kinda rough sometimes.... Seems like lots of people has transmission issue...

konigstiger

Repair is covered for 12 months/unlimited mileage bring it back, speak with the Service Manager and request MB rep covering dealership oversee/moniter case.

ts350z

Thanks for the info