Not too worried in fact I kind of like it but I'm wondering what causes my problem. My TC doesn't unlock when I let off the throttle. Go on the brakes and it works OK. when it gets down to about 20mph (in 3rd) it unlocks by itself and sometimes if I blip the throttle it will unlock. It's like having a free ATS Copilot. It did this awhile ago and then cleared up for a year and now it's back. Shifts fine otherwise. I'm thinking APPS or something throttle related. Any idea's?

What do you think this is?

I don't know, but it is a possibility of the lock-up solenoid sticking. How long has it been since the tranny has been serviced?

About 15k ago a new TC and total fluid change. Was supposedly rebuilt 33k ago before I bought it.

I tend to think the same thing I would look at the solenoid and see if its sticking.

Would a sticking solenoid only stick on throttle off? Unlocks fine when I hit the brake or go below 20-25mph. Just trying to cover all the bases before I take another ATF+4 bath.

Well, it fixed itself again. I wish it could've done it when my 53 block cracked.