Strangely I have trouble to find the low oil pressure sensor, which usually located near oil filter housing. Based on your finding, I wonder if there’s none actually? The oil pressure gauge uses the different resistance signal outputted from low oil pressure sensor. Mazda may use some other way such as getting some signal from Oil Control Valve, P/N: PE0114440A ?
I asked Chris where he pulled the pressure from for the gauge array he has in his CX-5. He uses an aftermarket adapter ring that goes between the filter and the engine block.
Interesting thought you have. So perhaps the pressure
is being sent to the computer.
I'll have to do some searching on OBD software forums to see if others have found a way to get to this. I dropped it when (1) I was told there is no oil pressure sending unit, and (2) Mazda was slow in providing the 2019 MY data to ScanTool. (I just looked, the extra-cost 2019 Mazda-specific PIDS were
just rolled out by them last month.)