OBD Code P0521

[7shot]

I am having the dreaded low oil pressure code P0521. The oil pressure on the gauge starts off normal until the engine warms up then drops to around 20 PSI when at normal driving speed. But at an idle it drops to around 8 -10 PSI and causes the check engine light to illuminate. I have removed the filter under the oil pressure sending unit, replaced the sending unit twice, changed oil and filter multiple times. The oil pump has also been replaced. I do not have access to a mechanical oil pressure gauge but there is no engine noise when the pressure is around 10 PSI on the gauge. My question is how do I go about troubleshooting the wiring harness or the electrical side of this issue. Thanks.

[newdude]

I would get a mechanical gauge on there first then worry about the electrical side. Screen is supposed to be there as well not removed on AFM engines.

[dasimmon]

http://www.gm-trucks.com/forums/topic/169782-attention-anyone-with-oil-pressure-issues/