I have a S10, 2000, 2.2 liter with 4L60E automatic transmission. The trans was rebuilt just before I got the truck and I verified this at the shop that did it. It's got about 45k on the trans since this rebuild. It started jumping in and out of TC lockup intermittently not long after I started driving it. No codes set and no light at all. I took it to the same trans shop that did the rebuild and drove it with a scanner and it wouldn't malfunction for them and they saw no stored codes. Then it went for several months and only slipped in and out once in a while so I lived with it. It started getting bad again so I took it back in and it acted normal again for them. I said if I drive it to work and it does it on the way I’ll come by so they agreed. The next day it started going in and out after about ten minutes down the road so I went straight to the shop. By the time I got there it wouldn’t go to lock up at all. He drove it with me and the scanner showed the TC was not being told to go to lock up. He said the trans wasn’t at fault. He could see the temp was steady and OK, the TPS (throttle position sensor) was a little low but steady and not the probable cause and VSS (speed sensor) was steady and looked good. He said he could only guess the computer was bad. I’ve since replaced the computer, TPS, and the VSS with no luck. I’ve ohmed out the wires and connectors from sensor to PCM connector as far as I can reach for each of these parts and find no broken or shorted wires. It seems to get worse when it warms up to the point it won’t lock up at all now. The temp gauge is rock steady so I don’t think it’s bad or the wires. If I drop it down to 3 it seems to work fine up to what seems like 4th gear. I’ve tapped the brake pedal and pulled up on it with no change. I’m at a loss now since the trans shop says the trans is good. Does anyone have any helpful advice?