Coolant leak
 

https://cimg6.ibsrv.net/gimg/minicoo...63106e173a.jpgThe naked connector is leaking.
I have a major coolant leak on my 2011 Clubman S manual transmission. Seems to be from the sensor in the pic. It's behind the coolant tank on my car. I've owned it for a few months and have always wondered why there was no wiring harness connected to it. I'm wondering what it is for. I can't identify it with my Bentley manual. Is this a common location for leaks? Any help will be greatly appreciated!!!