05 S55 AMG Tranny issues

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Sep 20, 2017 | 01:30 AM
  #1  
Out of know where, my transmission has stopped functioning properly! First symptom, too high RPMS and not upshifting. Herky jerky shifting. Then down shifting on its own and refusing to upshift with accelerating. It has done this in every setting and was also reset 3 times with no change. It was serviced a few months ago and I believe there was a code but I would have to search for it. The fluid was checked an it is correct! Any help would be appreciated!
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Sep 20, 2017 | 10:22 PM
  #2  
Take the TCU out and turn it upside down. I'm sure you have tranny fluid in it....if you do you need to clean the wiring loom and replace the Transmission Adapter Plug (A2035400253). Then you have to pry the TCU box open and take out the board. Wash it clean with brake cleaner and make sure its ALL THE WAY DRY. Also wash out the TCU box. Re-assemble and take her for a good ride. If you have someone with star have him clear the tranny adaption.

Good luck.
Reply 1
Sep 21, 2017 | 10:06 PM
  #3  
Just thought about one more thing....could be the input shaft speed sensor in which case you need to change the conductor plate in the tranny. BUT that SHOULD give you a code and the tranny should go into limp mode so i would still refer to my first answer to check first and then move on to the conductor plate.
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