The P0520 is almost guaranteed to be the oil pressure sensor itself, at the rate they fail the dealers have a hard time keeping them in stock. I've replaced so many of them I can do it without even looking. On that engine it's hiding behind the alternator, you remove the serpentine belt, then the three bolts that hold the alternator on, just move it aside, remove the wiring connector and replace the sensor. You usually will see nothing outside that shows it failed but the common thing is the inner diaphragm between the oil and the sensor fails and they start to "stick" at a pressure other than zero at initial start. That trips the code even if the oil pressure gauge or information shows it's working. To remove it you need an oil pressure sender socket like a Lisle 13200
Nov 6, 2019 at 12:44 AM