I bought the gmtd scan tech software and connecting cable.I can't get it to connect to the truck. It keeps coming up as com port closed. I've tried plugging it in to every port on the laptop. Do I need to turn off the firewall or try to disable norton security?:mad2::mad2::mad2: Stefan doesn't seem to know why it won't connect. At the moment ,I'm feeling like I threw over $200 in the toilet. I know that it should work,but won't. Thanks in advance.