Hello, first post here and I hope it is an easy one.
I have a 2010 XF 5.0 non supercharged. Got this car cheap and working through the numerous issues, first of which is a high coolant temperature reading when the car is cold. Of course I checked the one that is easy to get to on the thermostat housing, it is good. In doing research I came across a second coolant temperature sensor supposedly on the rear right hand side of the engine. When I pin it out to the ECM I am getting 25ohms, which would make the ECM think the engine is hot.
So my question is are there two coolant temperature sensors before I pull the intake to see if one is back there.

THANKS!!
George

 

IIRC there is another coolant sensor which is part of the plastic coolant manifold at the rear of the engine (at least on the supercharged model).

 

OK, pulled the intake manifold. YES there is another coolant sending unit behind the intake manifold. This one is on the firewall and looks to be something with the climate control.
On the back of the manifold is a vacuum solenoid controlling two actuators inside the intake. Don't know what they do but Jaguar must have had a surplus of these gray plugs because they can be swapped if you happen to have both unplugged. Seems the previous person working on this car got them mixed up.
So now to swap them back and put things back together.

 

UPDATE, indeed the plugs were swapped. After putting it back together had the same problem, coolant temp reading 305 degrees. Pinned it out with a ohm meter and the coolant temp sender was reading five ohms. Pulled the manifold again and replaced it. All good now.
I actually think the temperature sensor at the back of the engine is primary and the one on the thermostat is the secondary.
Getting pretty good at pulling the manifold, looking forward to the timing chain swap in the near future. A little noisy now.