How you would calculate engine oil pressure of an engine? I've noticed on my car I just got, it uses a pressure switch in the oil system to measure engine oil pressure it seems in my case the switch has a threshold of 6psi to turn the pressure switch on. The dash will actually display a psi value that does change with engine speed,etc for oil pressure.

I am assuming the ecu is using a algorithm to determine the oil pressure I see on my display. This is interesting to me where exactly would you start to create a algorithm to determine engine oil pressure.


2 Answers 2


There are pressure sensors fitted to determine the pressure - similar to temperature sensors.

Been available for years and cars used to have pressure gauges either Bourdon or electric but they went out of fashion.

With all the ecu fitted on cars and the multilevel screens they may include them again.

Using odb readers can show a lot of instantaneous readings oil, fuel, turbo pressure etc There are pressure sensors for all of them...

  • $\begingroup$ Seems the one on mine uses a pressure switch only 2 pins on the oil pressure switch,not 3 pins like iam used to seeing.Also looking at the field service manual its called a oil switch $\endgroup$ Jun 4, 2019 at 3:56
  • $\begingroup$ Separate sensors is a possibility... have you checked the electrical diagram? And with two wires it could be combined - the earth or ground is often by the body - some sensors only have 1 wire... $\endgroup$
    – Solar Mike
    Jun 4, 2019 at 3:58
  • $\begingroup$ Yes i looked at the schematic its a SPDT switch looks it only has one wire,and is grounded through the body.Description also says its closed at a higher psi,and open at a lower psi value.Not a standard 3 wire pressure sensor $\endgroup$ Jun 4, 2019 at 4:29
  • $\begingroup$ so what happened to the two pins you mentioned? are you sure you are looking at the correct item? $\endgroup$
    – Solar Mike
    Jun 4, 2019 at 4:31
  • $\begingroup$ 2 pin connector on the switch,the schematic shows only 1 wire running to the switch its self. $\endgroup$ Jun 4, 2019 at 4:44

Found out there called virtual sensors which are designed in the ecu program code and use a neural network to learn and then estimate oil pressure using input from other sensors.


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