My 2011 MB E350 will not shift into gear after changing the transmission fluid, guide tube and filter. Is there a reset procedure or what could cause it to not shift?

To answer your question concerning the right fluid, check your owner's manual for that. Have a couple of ideas. Try moving through all gears on the selector and go slow on each one. Then have a look at your level again. If nothing helps there get in make sure the door is closed depress gas pedal all the way to the floor with key kn to first position (no start) hold pedal for 15 seconds then back to stop position. Wait 5 minutes restart and see if any difference. Only other option for DIY if that does not work is to just unplug/hook back up. Hopefully there is not an issue with the conductor plate or module related error. If that is the issue only way is to know for sure is with MB Star diagnostics. A basic OBD may or may not produce a generic code. Good Luck!

Try resetting the transmission module