2011 Chevrolet Equinox 2.4

My daughters car was running great, but then one day would not crank over. Used a jumper relay for the starter and it cranked over, and with the ignition on it started. Replaced the relay, and everything was fine for quite a while. Then later on it would seem like it was stalling for a brief second or two, until one day it would crank over, but not start. After some testing, realized it was the relay for the engine controls. Replaced that relay, but at this time decided to check the relay and fuse block. Took it apart, didn't find any corrosion or obvious faults. All the connectors were tight, nothing was loose. Replaced the relay and for a while everything was fine. Replaced her valve cover gaskets and timing chains, shortly after, got a code p1682, and vehicle would not start. Started to check the grounds, found a short from the pcm ground. Repaired wire, everything seemed fine for a while. Went to fix an exhaust leak at the manifold, and ran into the p1682 code again. Key on showed engine in limp mode, would crank but not start, no power to coils. I know that this points to an ignition switch issue, but only happening when I'm moving wiring around has me thinking its a wiring issue.  Have various resistance readings for this circuit depending on where i test, but I cannot find a good wiring diagram to figure out the entirety of this ground circuit. I don't think I was burning relays, I think I was just losing a good ground. I did check all the grounds on the engine and chassis but I am striking out at this point. Vehicle was bought used recently. 140,000 miles.