Finally got another chance to work on the truck again to try and figure out what was going on. After several attempts, I was able to connect to the ECM and write to it, but not to the transmission. After unplugging and plugging in connectors to no avail I decided to check the transmission plug. Plug was loose and pulled right out. I reconnected plug and started my truck and my ScanGuage II started working again so I hooked up my HP tuners and was able to write both ECM and TCM. Took truck for a spin and all is working!!!!
