Tack för dina förslag!

I had to mix a litle from both your ideas. The sensor seems to have a really weak internal pullup to 12V so as soon as I connect the resistor divider the voltage drops alot. And without the divider the PIC gets 12V on the pin.

So I ended up introducing a new pullup resistor to 12V to the output .. and then a resistor divider from that. Weird but working