Had same issue a few years ago. It end up being the Transmission cable adapter. The O-ring tends to fail and transmission fluid will leak and sometimes into the Transmission control unit. This cable adapter is readily available and quite cheap ~ 15 dollars from Amazon. Check this video out on how to change it. Not to difficult if you are willing to get your hands a little dirty. It's not the same car but uses the exact same transmission as the one you have. The 722.6 automatic transmission. He also drops the transmission pan becasue he was performing a transmission fluid change. Might be a good idea to do that if you haven't done that yet. Also you need to update your USER CP to include the model and year of your car. It's located on the top left of this page.

https://www.amazon.com/Beck-Arnley-...?s=automotive&ie=UTF8&qid=1500254155&sr=1-6&keywords=ml320+transmission+adapter

 

hello thanks for you response but it not the trans adapter but the lower end of the trans cable connect to the trans shift adapter seal. Although Im going to change the adapter as soon as I know if I have to change out the cable #119

 

If you still need help from the experts here, it's wise to complete your profile just so they don't have to ask you repeatedly.

 

Got the profile Done Thanks!

 

It is not a cable that is leaking. It's linkage inside that cable connects to.

http://www.benzworld.org/forums/w16.../forums/w163-m-class/1398042-trans-fluid-leak-need-some-help-3.html#post3078299

Here is thread with more details.

http://www.benzworld.org/forums/w163-m-class/1462266-linkage-parking-shift-lock-update.html