2001 tdi jetta auto problems

So I have this 2001 jetta tdi auto.When I first bought it I degreased the engine.Whala check engine light and transno shift,limp mode in 2nd...
Let it dry for a couple of days and it decides to work correctly.Now 2 months later we get a large amount of rain and guess what? MIL and no shift.
I am unfortunately still missing the lower side shields on engine bay!
am trying to locte a pair I am going to call dealer for pricing today!

A: has anyone had this happen to them?

B: Where is trans control module located

C: What is the box on drivers framerail under battery with 2 connectors?
one has 4 wites 2 of wich are extremely heavy gauge wire and the other connector has like 10 small wires.


Thanks for any info on this as I am still new to these newer vw's

So, does this car happen to have a sunroof? I have heard of water leaking into, and causing problems with the TCM when there is a problem with the sunroof draining incorrectly. Also, there have been issues with water affecting the electronics of the transmission in other ways. This problem cooresponding with the rain might be a clue.

Yes sun roof.No I am certain that the rain is def. the culprit.Anybody know where trans controller is located?

The TCM is under the front wipers, on the right side (in the direction of travel).

The multipin transmission plug is what you should be looking at. Its weather seal could be bad, or it might just need a contact cleaning and a coating of dielectric grease (on the shell, not the contacts).

outside in the coul?

Yes, for the TCM, but I'm referring to the 16 pin solenoid connector on the transmission housing.

on the rear upper? checked it already,clean and dry unfortunately.

is there a connector at the trans in the front ?I checked the one on the top that then leads to the front and behind the skidplate on trans.Is the ridgid gray "cable" that goes from the top to the front lower for the solenoid pack?
Thanks for ant info.

It's easier to show you than to try to explain it.

This is from coolairvw:

Thanks,I have checked all of those for moisture and corrosion.Unfortunately all are good.I am curious about the solenoid cable now.The first time it did this it had a solenoid fauld code.(cant remember wich) I am going to take it to a friend of mine who also has a shop and have him see if he can point me in the right direction.I am at the end of my rope wit this thing!

Well It has been solved for now anyway.There was a code for a faulty vehicle speed sensor.Recorded the code and erased,new sensor ordered.Drives fine for now.Ordering the new side shields also on monday.
So far so good!