what is this?????

what sensor is this???
my friend and i were swapping harnesses (he’s got a 90 crx, and swapping in b18a1)… his crx harness didnt have a plug for that circled sensor. and i couldnt find it in the helms… not that i see all that well LOL… anyway. does anyone know what this sensor is for?

thanks, btw, this came outta 90 4d teg GS

That is weird, i am not sure but it almost looks like the ECT
(electronic coolant temperature sensor), But that would not make sense considering the particular sensor is on the cylinder head.

Looks like it was custon done. I know it is not a knock sensor.

If i am not mistaken, there is suppose to be a regular plug in place
of that sensor, as i said it looks like it’s custom done.

the weird thing is, i checked my engine block, and mine has it too.
i know for sure its not a knock sensor as the b18a’s didnt come with them.

well i figured it out…
the sensor that’s circled is the Engine Oil Temp switch…
the other two are the ECT (engine coolant temp) and the Oil Pressure sensor…
the ECT being above the oil pressure sensor.

now the hard part is figuring out how to wire in the Engine Oil temp switch… since the CRX doesnt have that in its harness…
that Engine Oil Temp sensor goes into a radiator fan control module which then turns on the fan when the oil gets too hot.

grrr… whatta PITA