eclassw213

Hi guys,
After searching through this and several other forums, i cannot seem to find the solution to my weird problem. I have a 2007 C200K (W204) with 5-speed automatic (722.6 i believe). Only in second gear, when i give light throttle (30-50%), the car launches fine, but before shifting to 3rd it gives a jerk around 2k rpm, the rpm drops to 1.5k and then rises again to around 2k and then shifts to 3rd. It only happens in the second gear, the rest of the gear shifts are smooth. Happens both in C and S mode. It also happens in Manual shift mode, e.g. if i force the car to keep in the 2nd gear by selecting it manually, it will launch fine, but around 2k rpm i get this slip/jerk and the rpm drops to 1.5k then normally goes upto 6k. I am puzzled what this could be. would be great if anyone can help on this one? I will make a video of this later, but i found another video from someone having same problem(without solution):

alecmascot

Check the ATF level.
There should be a dipstick tube, but you will need to buy a dipstick

Agent-A01

Can you change your TCC solenoid for the torque converter in the valve body and get back with us?

eclassw213

I actually am thinking in the same direction. since this would not be a cheap thing to do, take out the valve body and replace TCC solenoid, i have a followup question. is this something that can destroy the tranmission completey in the long run? the small bump which i feel is still not uncomfortable, and it only comes in the 2nd gear. I only drive the car long distance, so for me is not that big of a deal.

xsever

The 722.6 transmission is known to suffer from problems with the conductor plate and/or some shift solenoids which can result in what you're faving. Low fluid level can also be the cause.

Can you get the car scanned with an MB scanner (STAR/DAS/Xentry) and pull the transmission control unit fault codes? These will help us properly diagnose rather than throw parts at the car.

eclassw213

That is a good idea. let me schedule an appointment with my free workshop and try to pull the codes. A stupid question, the transmission codes can be read with STAR from the OBDII socket? or is there a special way to do it elsewhere. I question since i have a OBDII reader from Bosch, so maybe i can try myself to read the codes.

eclassw213

Actually i found the following link (in german):
https://www.derpade.de/anleitung-mer...wuek-wechseln/
This is exactly what is happening to my car. so i figure is either the TCC solenoid or if i am super unlucky the complete conductor plate, valve body etc.

xsever

Yes STAR connects to the OBDII socket just like your Bosch one.
I am not sure how sophisticated the Bosch scanner is. If it's a generic OBDII scanner, it cannot read the proprietary MBZ fault codes which give much more information. If access to the workshop and STAR is free, go for it right away. Good luck.

laiayo

Hi, did you replace your TCC solenoid?
I have the same symptom RPM drop from 1600 to 1500 in 1st gear and drop from 2300 to 2200 in 2nd gear.
the jerk happen in 3 modes (C, M and S)