Noticed this while looking for a spot to tuck the block heater cord I also just discovered. Seems curious...

 

I'm guessing it's radar for Automatic Cruise Control?

 

external temperature probe I think

 

Ahh, ext. temp makes sense thanks.
No adaptive cruise on the old girl.

 

I do have Adaptative Cruise Control on mine and I do have the same sensor.

 

Interesting . Nothing in my manual about it. I'm pretty confident my car is not so equipped but I've been wrong before.

 

and I don’t have any others then this one too

 

Press the EXT button on the climate control panel and it will use that temp sensor to displays ambient air temp.

 

Is that all it's used for or does it also talk to the ECU?

 

There is a temp sensor in the MAF, that is what the ECU uses.

 

Thank you. I know my external temperature display is wrong so I was interested!

 

For future reference this is the infamous ACC radar module:

 

Any information on its location
Thank you

 

Behind the front bumper in the middle - probably all corroded now, externally and internally. Inside it has a motorised radar reflector which scans back and forth - this no doubt stopped moving years ago. Great bit of technology when new though.

 

I will give it a look as soon I take the car out for a road trip. My XK8 2006 Victory Edition has a Adaptative Cruise Control and Forward Alert (Advance Accident Warning System, probably the same sensor for both), and both system works perfectly.

 

They revised the design in 2004, with a different type of actuator and a contactless position sensor - sounds like it was a good improvement.