Alright guys I have a crazy one that is baffling me. I have a 2002 with 32023 miles. I removed the trans to fix a front pump seal. No big deal as I've done many in 4L60e's. So I removed the trans and replaced the front pump seals. I replaced the gasket, the pump o-ring, the converter lip seal, and the stator shaft seal. I put the trans back in and took the car out on a trip. After too long drives the SES light came on and the trans had harsh 1-2 shifts. Found the code to be a P1870. Went thru the diagnosis and figured I must have torn the stator shaft seal when I went back together. So I removed the trans again. The stator shaft seal didn't look bad but it was aftermarket. So I ordered new OE gaskets and replaced all of them again while the trans was out.

Reinstalled the trans and puff the TCC slip speed was anywhere from 150 to 280. Did some more searching, and from prior experience it appeared that the torque converter was bad. Talked to a few people including a buddy that owns a trans shop. He agreed with my thoughts on the converter. So I removed the trans and installed a new converter. Well guess what still the same TCC slip.

So I continued to play with this thing. Checked the wiring to the PCM and found good. Tried new TCC solemnoids, both the enable and the PWM. Tried shiming the TCC regulator apply valve. All didn't change anything. So tonite I tried a new PCM because it was the last thing I could think of. Well of course no change.

Sorry about the long post but I figured I would tell you guys most all of the story. I'm hoping someone out there has had a similar problem and can tell me hay you idiot this is it. At this point I think that it must be something I did. If anyone has any ideas please let me know. Thanks guys.