ACV

I have a 19 with 89k on it. Since December I've had an intermittent check engine light come on. At times it will cause truck to shutter and go into reduce power mode. Multiple codes show up with the main one being P0641 (sensor reference voltage A circuit/open) along with P0016 (crankshaft position), P0106 (Manifold Pressure), P018c (Fuel pressure sensor). My assumption is there is a wiring issue causing multiple codes to go off. Seems to happen when it is raining or high humidity. I have an extended warranty until 90k and have had it into the GM dealership 3 times. The first time they repaired 5 wires on the main engine harness. The problem persisted and will continue to give a check engine code however will shut off and turn on randomly. GM says they can't do much unless the check engine light is on? There seems to be multiple bulletins on main engine harness issues. Any thoughts on source of issue is much appreciated. Love the truck but can't trust it at this point.