dgncsk

Dear friends, this is my first technical post/question here. I hope i can find asnwers as quick as possible and i can share my knowledge where ever needed in future.

My mom has a w204, with a small engine 1.6 kompressor. 156 hp 5 speed AT transmission. it is 2010 make. Odometer is on 12K miles only. She drives this car between home and her office each day. Car is totally stock. Only repair done was bumper painting due to a scratch in a parking lot.

She mentioned few times about a hesitation on car in past but during my trips with this vehicle i was extremely happy with it. No problems at all.

Last week car stuck at 1st gear and we were able to shift gears by manually on pushic stick to sides. After moving the car, one were able to shift gears either manually or automatically, please note that shifts were delayed and car were sticking on gears longer like it is in sport mode. 1st to 2 nd shift was achieved with a thump feeling, extra harsh.

Then Check engine illuminated, two codes one was u0103 other vas U0002
I checked with my Scangauge and found that those codes can be just a simple connector problem or TCM itself.

I went ot MB dealer and asked them to check, they found that transmission control module or the PCB itself problematic and they commented that Torque cOnverter is alos problematic. I asked them to replace the controller first. They did so and changed the oil an filter.

Shifts and revs are normal now, no harsh gear changes or engine codes except shuddering right before stop. It happens right between 15kph-13kph. (~9 mph - 8 mph). it acts like i forgot to press clutch pedal on manual transmission car for a second, rev decreases to 500 rpm and it releases and car returns back to normal before stoppin. lets say 800 rpm.

According to them, this is beacause of problematic TC.
I ask why? car is still so new and driven well and gently in 3 years. Is there any reason to have such symptom? A selenoid inside transmision? old spark plugs? they ask USD2500 for a new TC. i dont want to pay.

Glyn M Ruck

It seems that the torque converter lock up clutch is not releasing properly. Ask Benz for some assistance with the repair at such low mileage. Get the factory representative involved.

dgncsk

thanks for quick response. actually this is what they propose. they asked me to come once more, after few days and let them open a file for this car. they will contact to factry in Germany. since car is out of warranty, and had only one oil service in an authorized dealer, ( stupid rules ) ,they think that Benz will not be easygoing on this issue. ( since we missed the second one becasue car went out o warranty period after two years)

i have limited knowledge with AT trasmission in contrast of engine mechanics. I dont like AT systems but these are most popular in crowded cities thesedays. Where is this clutch. if problem is directly related, how to repair? Is it really related to TC? TC is a big donut and filled with oil. There are openings to transfer oil one place to another, isnt it?

Glyn M Ruck

Your transmission has the same TC as the 722.9 7 speed.

dgncsk

too complicated than older cars. it is quite interesting to have locking Tc on all gears. it seems this thing is not servicable and it should be replaced as suggested.

how is lock up clutch being controlled? mechanically by oil pressure?

Glyn M Ruck

Oil pressure