Perfect Engine Management System

Checking to see if anyone has this management system on their car http://www.painlesswiring.com/Manuals/65245.pdf I have the disk but not the key or communication wire. I'm told without the key you can't communicate or talk to it and this system is not supported and out of date.
I wouldn't care and would not bother with this, but I get a diagnostic light coming on and off during a 20 -30 minute run. Car runs fine otherwise but would like to know what is triggering the light.
Really don't want to update the management system if I don't have. Any info would be appreciated. Car has LS motor