2-Pk Kobra Professional OBD2 Diagnostic Car Scanners

I figured out how to use it and it works ok. But I consistently get no codes and my AT light (transmission) comes on frequently with cold starts. I turn off engine and system reboots so nothing in the code for it. I'm guessing it's the input speed sensor. A mechanic couldn't get a code read either with his device. So I guess it has to be the CEL (check engine light) that comes on for a code read. I was able to get the VIN with this scanner. I don't know what else to say except that it doesn't scan AT light problem and you have to turn engine and ignition off before scanning and AT light disappears. Still I can't complain as I got it for under $13. w/ free shipping on a prime trial.