1996 Cherokee Country 4L 4x4 AW4 trans 250,000 miles - Wife's Cherokee. Awhile back it started "hunting" in D between lockup and non-lockup when accelerating up a slight grade, and I drained the trany fluid and refilled with Dex3 and a bottle of Lucas Trans-fix. It soon stopped hunting, but I suspected it no longer locked up.

Recently it intermittently stopped auto shifting to 1st at a stop, especially after it warmed up, and more recently stopped auto shifting to 1st when cold too, but always gets 1st manually moving the shifter to 1-2 position. I unplugged the TCM and did the manual shift test - 1-2:stays in 1st, 3:stays in 3rd, D:stays in 4th (can't tell if it locks up, but I don't think so.) I've also re-set the TV cable per the push the button, slide the cable in, and let it ratchet out at WOT method.

So...are these symptoms of a bad TPS, a bad TCM, a bad sensor, or something internal? I have a new filter and planned to clean the pan and install the filter, but need to know if I should check internal things while the pan is off. Also, would the TCM from my 90 Limited (same engine and trans, I believe) interchange with the 96?