Hi, could anyone advise why my jag xf 2.2 diesel r sportbrake at cold start the engine cooling fan starts straight away and the temp reading in the car say minus 1 when its 10 degrees and sunny? . Thanks

 

You really need to pull the DTCs from the car to start diagnosing this, but you've got some clue there's at least one fault because it's telling you it's 12 degrees colder than it is, which seems like a problem with the ambient temperature sensor, from memory that is in the LH wing mirror. It could be the car is getting conflicting or inconsistent temperature readings from various sensors, which will cause random things to happen.

The fan will come on when either the engine or AC rads need cooling. A fault in any of those systems, including temperature and pressure sensors, may turn the fan on - it's the fail safe mode. Also the fan has its own controller, if that is faulty it might also stay on.