Morning all, I need help diagnosing a possible electrical issue with my 2002 C5 Z. Ive been back probing wires on engine wiring harness and my LS2 Throttle Body 5V ref wire (yellow) is reading battery voltage when key ON eng OFF. Im no electrical wizard, more like a dummy, but I dont think thats correct. Do I have a short or bad PCM? How would one go about tracing this back to find the culprit? THX!

Here are my TB volt readings: PNK=0V YELL=12.5V BRN= 12.5V GRN=5.0V GREY=0V.
MAF volt readings are YELL=5V.

I do have a Tech2 scanner...