When I bought my replacement tranny, I was given a module with it. I was told by them it was the TCM (Tranny Control Module). Now from what I have read the 2005 Dakota has the ECM and the TCM combined as one PCM.

The module has two part numbers on it. P56049 and P56040. I did a Bing search, on both part numbers, even an eBay search, couldn't find anything conclusive.

I did find where it is installed. It attaches to the back of the underhood fuse box, which leads me, even more to believe that it has nothing to do with the tranny.

So what is it? lol

 

Maybe the FCM? Do you have a picture?