Hi Guys, My name is Vipin and I am new to this form. I purchased a 2005 E55 and been having some problems with my transmission. The transmission was shifting fine from 1st-3rd gear, but when it would want to shift from 3rd to 4th gear, it would just free rev and act like it had gone into neutral. I got the entire transmission rebuilt because it was having shifting problems. While I was getting it built, I also upgraded my torque converter to 3000 stall and got the valve body ported from IPT along with the blue top solenoids. Long story short, after the rebuild the car drove fine for about two months and then it started doing the same thing. One day I was driving to work and the car just free revved again when it was trying to shift from 3rd to 4th gear. I was told by my mechanic that it was an electrical problem and that i needed to change my converter plate...So i did. They also found some fluid in the 13 pin connector and the TCU module. My mechanic cleaned the TCU and changed the 13 pin connector along with the converter plate and did a full transmission flush and filter change. The car was driving fine for 5 days and the problem came back. Whenever I was driving in the S mode, the car would repeatedly free rev while shifting from 3rd to 4th gear, but when driven in M mode, the car would drive fine. Few days ago, I was driving on the freeway in M mode and while shifting from 4th to 5th, the transmission seemed to hesitate while shifting into 5th. The shift was delayed with a hard kick. After a few minutes when I tried to shift again from 4th to 5th, the transmission popped out of gear and just free revved. This was the first time it had done this to me. After parking the car and shifting it back to Park and shifting it back to Drive, the car started moving again, but this time i did not shift the car into 5th, but it seemed to shift fine from 1st to 4th. The car does not seem to be in limp mode but something seems to be going wrong with the transmission. I also bought a second TCU module but it did the same thing when I replaced it with the current one that I was originally running in the car. I been researching about this problem for a while and just cannot get around to finding out what the real problem is. The 13 pin connector seems to be fine and not leaking and neither is there any fluid in the TCU module. Could it be that i would need to replace the wiring harness which goes from the 13 pin connector to the TCU module or could it be that I need to replace my Valve body? But the transmission had this problem before i got the valve body ported and rebuild as well. I need your guys help in desperate measures since I am tired of spending so much money on problems which are solving my issue. Thank you.