P0521

Tech discussions on the L77 6.0L V8.
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Jaked1985
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P0521

Post by Jaked1985 »

I'm getting ready to stick a fork in this CEL.. This code for Engine oil pressure sensor/switch range performance is driving me nuts...

So far, I've determined that the screen under the sensor is m.i.a., checked pressure with a manual gauge, 20 psi at warm idle in gear. 30++ driving.

I've replaced the sender with a new delco piece and a BWD switch from advanced. Both yield the same results, I clear the code and sometime within the next 30 miles it returns. Could be 10 miles, could be 30, no rhyme or reason it seems.
I'm down now to a possible broken/damaged wire, does anyone here happen to have a diagram showing where the 3 wires from the sending unit run to? I've traced them back through the driver side injector harness to the front of the engine, but stopped there hoping someone might have a schematic, to save me from tearing apart the entire engine harness...

Or, if anyone has any other ideas that I'm missing, please chime in. The car runs fine, but, I'd like to get rid of the light and be able to install remote start sometime in the future.
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Mooseman
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Re: P0521

Post by Mooseman »

I get the same code on my Saab 9-7x with the 5.3 when the oil is about halfway through its life. Back story: I took out the DOD hardware and replaced the oil pump with a regular LS pressure and volume type. Right away I noticed the lower pressure readings. A few months later, I get the CEL and code. Replace the sender, same deal. Finally find out that the DOD system uses a high volume and pressure pump because of the bypass in the pan. So that code is related to the DOD system.

Now in your case, I would assume that your DOD is still functional? Those pressures are low, DOD or not. Check for that screen and replace it. You could also try to use another port to get another reading. The one at the front left that is usually used for priming is a good one. If it's still low, I'd look into the pump, the seal between the pump and pickup tube or the pickup is clogged.
2011 Caprice PPV, former RCMP test vehicle, never put into service
Build Thread: http://www.newcaprice.com/forum/viewtopic.php?t=2419
smwalker
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Re: P0521

Post by smwalker »

Looks to be straight to the ECM:

Image

If you have a multi meter check for the 5 volt reference and a good ground.
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
Jaked1985
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Re: P0521

Post by Jaked1985 »

Mooseman wrote:I get the same code on my Saab 9-7x with the 5.3 when the oil is about halfway through its life. Back story: I took out the DOD hardware and replaced the oil pump with a regular LS pressure and volume type. Right away I noticed the lower pressure readings. A few months later, I get the CEL and code. Replace the sender, same deal. Finally find out that the DOD system uses a high volume and pressure pump because of the bypass in the pan. So that code is related to the DOD system.

Now in your case, I would assume that your DOD is still functional? Those pressures are low, DOD or not. Check for that screen and replace it. You could also try to use another port to get another reading. The one at the front left that is usually used for priming is a good one. If it's still low, I'd look into the pump, the seal between the pump and pickup tube or the pickup is clogged.

I guess I should of added a few more details, the DOD has been deleted by the previous owner. I shot him a message to ask what oil.pump he used and he said it was just a regular LS pump. So, I might be looking at the same issue you're having with your SAAB, only in my case, it doesn't matter how old the oil is. The light trips within 30 miles of clearing the code.

The car will run up to 50-60 pounds with I hit the gas, maybe I need to look at replacing the pump with a high volume high pressure pump? He also mentioned that the bypass plug was left in the pan, so, I suppose now would be the time to plug it. If I replace the pump.
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Mooseman
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Re: P0521

Post by Mooseman »

I hate that our cars don't have an actual pressure gauge. On my Saab, when the pressure consistently runs below 40psi on the gauge, it trips the code. I can usually cure it by changing the oil or adding some Lucas oil additive (which is a thick goo) to bring it back up.

If he just put a regular pump, then that's likely the cause like me. Melling has the 10355 that is a high volume pump specifically for DOD.
2011 Caprice PPV, former RCMP test vehicle, never put into service
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Jaked1985
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Re: P0521

Post by Jaked1985 »

Update- replaced pump with high pressure/high volume melling, replaced pickup tube and oring as well and plugged bypass in the pan. Oil pressure is better, code is gone....for now.
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Mooseman
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Re: P0521

Post by Mooseman »

Which pump # did you use?
2011 Caprice PPV, former RCMP test vehicle, never put into service
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Jaked1985
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Re: P0521

Post by Jaked1985 »

P/N 10355
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Chevy-Art
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Re: P0521

Post by Chevy-Art »

Jaked1985 wrote: Sat Dec 01, 2018 3:43 pm I'm getting ready to stick a fork in this CEL.. This code for Engine oil pressure sensor/switch range performance is driving me nuts...

So far, I've determined that the screen under the sensor is m.i.a...
Is the screen needed? I would rather not have it. I think that the 2500 trucks don't have a screen.
2013 Chevrolet Caprice PPV Hugo Blue
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