Thanks to Psi,
you made my day

I just started to search before reading the second line of your post...
@jpanhalt:
to be honest, I received this controlled from a friend who's working in a JD service center. He ask me if I can search on component level because those spare parts are running out of stock.
I disassembled the 3 sensors and measured the values.
They are variable resistors with 4k7 ohm max value. It seems to be linear.
I saw that the connections into the resistors are dark black/blue. I would guess they received some humidity or some other dust (

).
My first try would be to find other resistor give the PCB back to my friend for testing (without housing). Let's see if this is the issue.
Br.
Axel