96 GC Trans Problems Limp Mode

[lmdew]

I picked up a 96 Grand Caravan 3.8 engine 4 speed trans. 147K on the Van, the trans was replaced by a dealer at 35K with a trans that has a 1999 build date.

I have changed and flushed the trans fluid and filter. The pan was clean other than normal fuzz on the magnet so I do not believe the clutches are bad.

If I reset the TCM (turning off the car in neutral and restarting) the trans shifts fine until it goes into drive. It goes into neutral and the engine revs.

I can shift through L 3 D while this is happening without any changes. After a minute or so, it drops into the Limp mode.

The filter and fluid change had no effect. I tried a different valve body (from a wreck) and its still doing the same thing.

No codes with my OBDII reader.

Where should I go from here?
Thanks