I have a 1994 S10 Blazer with a 4l60e. On start up, transmission shifts through all the gears. Once I stop at a stop sign or stoplight the transmission goes into a limp mode, third gear only with a manual shift from second. No codes on tech2 scanner. With the scanner on live transmission data, and truck cold, it reads transmission temp at 206 degrees. If I unplug the harness at the transmission the temp goes to -40 degrees, then when plugged back in the temp reads normal (85 degrees). If I cycle the key off/on the transmission temp goes back to 206 degrees. Tech 2 also shows a "3-2 Control Feedback Fault". I've replaced the Ignition Switch, Pressure Manifold Switch, installed a new internal harness with no change. Any help or direction on how to test without throwing more parts at it and wasting money would be greatly appreciated.
