Hey guys I got a 07 ss trailblazer I been working on for 3 months. The problem is the u0100 no communication with pcm. I got another pcm no luck the brought a new pcm and new bcm. Still now luck it's getting power and ground to pcm. But I noticed don't have a 5volt reference. Also I noticed that my battery gauge sits and moves back and forth between 6 volts and 12 volts.