2007 Chevrolet Impala 3.5L Engine P0522 Code: Erratic Oil Pressure Warning and Oil Contamination at PCM

I own a 2007 Chevrolet Impala with the 3.5L V6 engine, and I'm currently experiencing Diagnostic Trouble Code (DTC) P0522. The issue manifests when driving: the oil pressure warning light comes on intermittently, sometimes after just 10 minutes of driving, and then goes off when I stop the vehicle. In some drive cycles, the warning light does not appear at all even after shutting down the engine. I've already replaced the oil pressure sensor, and confirmed that all wiring connections are secure with no pin drag issues. I’ve thoroughly inspected the three wires from the sensor to the Powertrain Control Module (PCM), and they all show good continuity. However, I noticed a small amount of oil at the PCM connector—specifically on the gray wire (5V reference) and a bit on the black wire (ground/reference terminal). This suggests that oil is being wick up or pressurized through the wiring to the PCM. I removed the PCM back cover and inspected the internal board, but no visible oil was present. I can only see a minimal amount of oil on the surface beneath the board. Has anyone else encountered this issue? Is it possible that the wiring harness is compromised or that the PCM itself needs to be replaced? Any insights or recommendations would be greatly appreciated.