My ambient temp sensor hasn't been too accurate. It's been either slow getting to the right temp, or as much as 20 degrees off.

Does the ambient temp sensor communicate with the interior sensor to control interior climate?

I thought I read that the exterior sensor might reduce the amount of "coolness" delivered to the interior if the temp sensor doesn't think it's as hot as it is outside.

 

When my ambient temperature sensor failed I had difficulty getting heat. It was mid-December and the sensor told the climate control it was 136 degrees outside. Could only get A/C brrrrrrrrrr. The sensor is inexpensive and easy to replace. I purchased on from JAGBITS one of the forum sponsors.
The work around was to manually set temp select on high for heat. It bypasses the auto sysem.

 

Mine read outside temp. -1 c. so a/c did not work dont know wear it will be on your car mine is on the right front behind grill cost in the U.K. £22 from jag.garage did this last week a/c now perfect.

 

Someone mentioned that the seat heaters are somehow affected by the outside temperature sensor. I think he was right.

 

Good to know info. Guess it's the same for the XJ8 series also..........
Thanks to those who replied.