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Discussion Starter #1
I've been getting the P0521 oil pressure sensor out of range code for some time now. It seems to be quite random, and the oil pressure looks fine on my aeroforce gauge when the code pops up. Since the pressure shows as fine and presumably comes from the same sensor that the code is triggered from, I don't believe that there's an actual pressure problem. I've replaced the sensor, but the code still persists randomly and can be shortly after startup or while driving after some time has passed. From what I've read, it pops up when pressure is read to be below 1.6 psi or over 128 psi, which suggests a short, open, or ground somewhere in the circuit that's probably so quick that I can't see it on the gauge.

Anyway, has anyone found a common point where the wiring for this sensor gets damaged? The wiring is in a pretty congested location (especially with a TVS installed), so I'm hoping to attack things with some strategy if possible. If I can't track it down, I may tune out the code and program my aeroforce to light up its annunciation lights if the pressure reads out of range so I can still monitor if it drops out but it won't trigger a code that disables my remote start. Hopefully I can track down the wiring issue, though, and any thoughts are appreciated. I've also had mice in the engine bay, so it's altogether possible that they chewed some things up...
 

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Thoes 3 wires jump into the wire loom that contains the injector an coil wiring. All of that wiring at that point, is hard wired back to the ECM. If the pin tension is good at the connector, I would say some in-depth meter reading would be required. That wire run in that area looks real close to the engine block back there. Probably a nightmare to work with considering all that equipment you've added to the top of it. They say it only takes 4 seconds worth of a signal breakdown from the sensor, to set that fault code. Like a temporary short to ground from the reference or signal voltage wires back to the ECM, or what the ECM thinks is an open wire condition from any of the 3 wires. Looks like it would be somewhat painful to masage those wires (as part of testing for good continuity of the wires from end to end).
Course the sensor itself could have been compromised (like with oil getting thru to the variable resistance device area of the sensor an messing up its output back to the ECM from time to time).
 

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Discussion Starter #3
Yeah, it's not very accessible. I looked over the wiring yesterday and couldn't see any specific damage, but it's tough to see. What seems strange is that there's definitely no noticeable loss of signal for more than 4 seconds that I can see. I have the pressure reading pulled up on my aeroforce gauge and it doesn't seem to be dropping out before the code sets (although I only look over after the CEL lights). Is there anything else that can cause this code to trigger other than <1.6 psi or >128 psi and corresponding RPM limits? I've now set the gauge to light up the annunciator lights if it reads below 5 psi or over 100 psi, so I should be able to notice it better if it indeed is dropping. It would be nice to know if it was a short, open, or ground that's happening to make probing easier, but nothing seems easy with this car these days. In terms of the sensor, I replaced it when I rebuilt the supercharger with new bearings, so it "shouldn't" be the problem.
 

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Proabbly neither here nor there, but was the replacement oil pressure sensor a genuine AcDelco? Are you using synthetic oil and/or oil filter? Read where at least a couple of people cured the light only after changing oil filters. Have not read of a common point where the wring gets damaged.
 

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Discussion Starter #5
Yeah, the old and new sensors are AC Delco. I do use synthetic oil and have always used GM PF48 oil filters.
 
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