What is triggering low oil pressure warning on 05 Passat 1.8

Its not the oil pressure switch next to the oil filter. It triggers whether the wire is attached or not.
I have proved that there is 25psi at idle and 60 psi at 2000 rpms.
Something else is triggering the warning on dash.
Does anyone know what it is?
Thanks!

glkirk said:

.................. It triggers whether the wire is attached or not...................................Something else is triggering the warning on dash.
Does anyone know what it is?
Thanks!

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Oil switch is normally open and closes with oil pressure to provide ground, what happens when you ground that wire with the warning going on. You can also just ground the wire and drive around and see if it sets off seeing that you have already verified that you have the correct spec oil pressure with a gauge. I modified an oil pressure gauge to mimic the VW tool so I can test switch and oil pressure at the same time, just need to hook up the wires and go for a road test.