Ground loops in Vehicle wiring loom

Hello,

 

Im looking at the ground schematics for a GM 2006 GTO vehicle grounding and i think i see at least four ground loops, are they ground loops? The PCM has 3 ground paths to the chassis/engine block. Do they not they affect the PCM and sensor operation?

Yes you are right i go with you.  Always gnd  should  complet their path in the shortest  route possible ,longer the route chances of emi is hi ,  not only that it can also effect your system operation by earth loop excess voltage ,but when you shorten the earth length by linking all the earth path to a single point and from there direct a single cable to the main  earth point  it helps to avoid emi/heating of the cable to an extend .but use appropriate  gauge for the cable.Sambath