Swap Grounding Gremlins! Tips on SENSOR ground please

The black wire with light blue tracer grounds through PCM at connector 1, pin 4. It goes to some main engine sensors through splices without going through the PDC but also goes to other items like cruise control switch by going through the PDC.
The PDC itself has joint connectors that have some of the ground wires connecting together, basically, and the few actual ground connections go out the square connector, that has 43 pins, out to a couple grounds.
Thanks for the info!
The black wire with light blue tracer grounds through PCM at connector 1, pin 4. It goes to some main engine sensors through splices without going through the PDC but also goes to other items like cruise control switch by going through the PDC.
The PDC itself has joint connectors that have some of the ground wires connecting together, basically, and the few actual ground connections go out the square connector, that has 43 pins, out to a couple grounds.
Thank you Bobzilla, yep it's exactly where you described. Time to order a shop manual for this donor! I'm now tracking the same wire around the harness to determine why I have one cut/loose end of the sensor ground mentioned.