Factory computer with a standalone harness from BP Automotive. It was a matter of figuring out what wire to tap into for the TCC function. The rear pigtail on the switch sees +12V at rest (brake not applied), then opens the circuit which actively unlocks the torque converter. I'll test it before any driving so that I don't screw stuff up.Having my 4l80e rebuilt as we speak. what conundrum are you having? What are you using to control it?