I looked wverywhere but all i meed is some possible answers before i proceed.
i have a 2010 c300 4matic. Have codes u0101, u0001, u0002, car drives fine , only symptom is when i stop at a red light i feel something like a tap where the transmission wants to go forward. Am trying to figure out where the tcm module for can communication is located, before it reaches the valve body inside the transmission. I found some moisture in the trunk on the right side by the fuse box. Checked connections and all are good. Fixed the small water leak. Does that box have anything to do with the tcm bus? Am sure this is the sam box.

 

Tcm unit bolts directly to the valve body.

 

my understanding is that there still is a module outside that connects the car to the transmission

 

No sir. Transmission control module is inside bolted to the valve body like it was mentioned before. Do you have description of the codes??? The codes are present in what module?

 

ya codes are up there in my 1st post. Not able to communicate with tcm. Am 100% sure there is a module for the tcm, I understand there is also the internal valve body and plates on inside, but there must be a module. The codes are from the tcm

 

I saw the codes you posted. Do you have a description of the codes is what I meant. The Transmission control module is inside the transmission. There is no outside module.

 

just says unable to communicate with the tcm. I checked the connection to transmission and it has a bit of oil on it so i unplugged it and cleaned it to see if it will make a difference

 

If you have no comms with tcm then its most likely faulty! This is why we do a short test with xentry and bases on all the codes from chassis units a better decision can be made. But the short story is if there is no comms with tcm and you have power at gearbox plug then just replace tcm. They do fail this way at times

 

i have xentry, let me see if i can get more info trom it. Weird thing is that it drives all day with no jerking or anything and only has 123k, hard to believe the electronics have failed on the inside of the transmission . This means removing the valve body correct?

 

I was under the impression that U0101 should turn on the CEL. When you check with Xentry, note whether codes are pending, stored, or active. If they are only stored, they may be from one time occurrences and can be erased.

 

No such thing as pending codes on xentry : They either current or stored. Do a short test post the results here

 

Don’t have Xentry. Thanks.