That is a temperature sensor. It can be used for ambient air temp or crankcase internal oil/air temp. The computer needs to know this data in order to 'compute' and dictate the amount of fuel required for each propulsion cycle. If you suspect it is faulty there are test procedures for it.
What year EV??
Since it is dry, I presume it is the ambient air temp. Probably should be located in the frame, somewhere up near the steering head? So, it probably doesn't matter too much where you reinstall it. Try to keep it away from engine heat and in a nice aerodynamic flow of ambient cooling air.
'98EV had an identical sensor embedded in the left valve cover to measure internal air/oil temp. But that would be oily upon removal. Later years had a better cylinder head metal temp sensor.
Patrick Hayes
Fremont CA