2013 Chevy Silverado w/flex fuel 5.3L with 142k miles. Automatic…..obd code P0521 and P0521P. This is my second time through this...swapped out effectively 3 years and 35k miles ago. So, I just swapped out the oil pressure sensor with a new ac delco oem part. Guage readings didnt improve and next day code popped back on. Do you think its a defective part? Or is there something else failing somewhere between the sensor and the computer?
If your Silverado has AFM read this:
https://www.mightyautoparts.com/wp-content/uploads/2019/10/tt-185-low-oil-pressure-message.pdf
Testing the integrity of the oil pressure sensor circuit is pretty easy.
It's 3 wires. 5 volt reference, Signal, Low reference (computer Ground).
To test the integrity of the circuit you just jump the 5 volt reference wire to the Signal wire (oil pressure sensor unplugged) and the oil gauge should go up to over 80psi when you switch the key ON.
Then check the resistance between the Low reference wire (computer Ground) and a good chassis ground. Make sure it's less than 1.0Ω.
