system failure visit workshop POR II help

[Eat-um-up]

My 05 997 recently decided to display the "system failure visit workshop" message. I did recently detail it. While doing so I did hear the horn honk and the lights flashed.. so I suspect I may have statically hit it.

I did everything by hand so no power tools. After everything seems to work. I have a POR II scan tool. It reads no DTC's when I search for DTC's under OBD II.

I don't see where else I can go to search for other non ECU codes. Does any one have this tool and can instruct me on how to read the code?