What is the empty socket under the 206 xr radiator?

Hello friends
the other day, when I looked at the oil while changing the oil of the car, I noticed a socket swinging under the radiator, that is, on the left side of the gearbox, in the crankcase.
I wanted to get some ideas from you.

Can the socket of the air conditioner be white color?

the tip was black, I take a picture of a socket coming out between 3 - 4 channel transmission and v apricot and send it to you

send it, let's see what the probe might be in the socket of the exhaust probe