Rigging up a transmission ground, good or bad idea?
 

I have a 1999 chevy 2500 C/K with a 5.7 VORTECH, and a 4L80E transmission. First and foremost, it has been having a hard shift problem, mainly from 1st to 2nd, but also 3rd to 4th intermittently. I got it professionally scanned and they said that the Pressure Control Solenoid is receiving no amperage.I tested the grounds and power going to the transmission, and the ground pin (D) for the PCS doesn't seem to have ground, while the power wire (C) has power. Is it most likely that the ground is faulty and causing the problem, and secondly, if I trace the wire can I rig a new ground to the body? Or will tracing the wire all the way to the problem and fixing it be the better option.

https://cimg1.ibsrv.net/gimg/chevrol...5c691c4a55.png

With Thanks,
Carl