2002 Intrepid Transmission

Our intrepid 3.5L with 135000 miles has been acting up a bit. Its had a couple hard shifts over the last few days/week that almost seemed like an engine hesitation, and this morning when slowing down from highway speed into a small town, it abruptly shifted down to 2nd and stayed there like its in "limp mode" ??.

Pulled over and checked fluid.
Level looked good and smelled ok but has a brown tinge to the pink fluid.

Started to go again and it still wouldn't shift.

Pulled over and shut car off. Checked codes P700 and P138.

Started car up and it shifted fine for the next 28 miles. Shut car off and parked it.

Any ideas?

Thanks for the help.

Solenoid pack failure, a chronic problem on vintage 02 to 04s.