Steps taken so far:
Replaced Oil Pressure Sending Unit/Switch with OEM. No improvement.
Changed oil and installed OEM filter. First 100m seemed to have less warnings.
Spayed out PCM and sending unit connections and applied dielectric grease. No improvement.
I've seen numerous posts identifying the sending unit as the culprit but far fewer with steps to take when replacing the switch does not resolve the issue. Hopefully I can add to that and also have some questions answered by those more skilled than me. Below is a snip of the FSM troubleshooting steps.
This specific table is for the 2.4L since the 4.0 only had steps for low pressure and not another for dropping.
Here is the 4.0 troubleshooting steps for reference. Im hoping I only ended up with a new faulty sensor. We'll see.
I picked up a manual pressure test gauge and plan to check for the recommended 13psi at idle today.
Spitballing here: Assuming I have adequate pressure, I was curious if there was a way to check the wiring harness for issues to rule that out. I'm a novice with a multimeter so my question for the group is if I would be able to check for continuity and resistance between the PCM and sensor? Below are thumbnails illustrating the PCM and Sensor's plug. Looks like I would be using CAV 1 on the switch and CAV 20 on the PCM. I also saw that the switch is supposed to be supplied with 5V, I plan to verify that as well.
I don't believe that the wiring is my issue, just want troubleshoot everything I can that is free before moving on to more expensive steps.