30 tire sizes...when the module itself is only capable of 3 ? Are you sure because I walked outside and hooked a DRB to a 2005 and it has 3 options, just like the guy said his MT2500 had.

 

I wallked out to my 2005 town and country, connected my snap on mt 2500 with black cartridge updated to 09. I can pull up over 30 different tire sizes on the trans function. IDK what ya'lls problem is but it's allowing me to put in a bunch of different tire sizes.

 

I went down to the used car prep/fleet shop and grabbed the tech's MT2500. His is also showing 3 tire sizes. You didn't buy your software cartridge on Ebay did you? You know, the Chinese knockoffs?

 

So, in the end it does not really matter how many choices I have. The correct size was already chosen, and was wrong. I tried both of the other choices, and neither made a difference. Also ran the "Cluster Calibration" test, and all went fine with no codes. Still my speedo is out by 15kph at 100. Just can't figure out what else to do. I can only imagine then when I do figure this one out, it will probably be something minute? Still, very frustrating.

 

There are 2 different ones on the DRB. One is a self test the other you can manually manipulate where the needle is pointing.

 

you said u rebuilt the trans and replaced the differential, right?
where did you get the differential? maybe he put in an higher final drive ratio differential by mistake?
you've replaced a mechanical part, maybe the problem is mechanical and not eletrical.
I havent experience TCM looses pinion factor memory due to a dead battery personally.

 

All that was changed, was some clutch discs, and the entire unit was cleaned out as little peices of metal were thrown all through it. The ring gear was the original one to. I know this, as I did the differential rebuild myself.
Yesterday I went for a drive witht the mt2500 hooked up. I tried selecting a different car that I knew would have a few more choices for tires(sebring it think it was). When I selected a fairly small 14" combination, the speedometer dropped aby another 10 or so at 100kph. So what I am assuming I have to do(albeit not really correct) is select a larger tire from some other vehicle. Maybe a 19 or a 18 or something. I just have to find some vehicle in the mt2500 that gives me that option.
In the end, it seems like something is off though to have all this crap so out of whack even when the correct tire was actually initially selected.

 

bigger tire size? what about Jeep? the Wrangleris off road size would do.

 

Did you resolve this issue? If so, what was the solution? I have a similar problem.

 

Problem is still there...just learning to live with it.