Says cooling sensor, but where is it located?

When cold the car has been reving a little strange, bouncing up and down between 1000 - 2500 but when sat in traffic last night i heard a click as if the fan was about to kick in but the check engine light came on instead. a quick rev and it went off and i heard the fans running.

anyone else had this problem.

 

Sensor is behind inlet manifold near to the turbo and sounds as though it needs replacing. Should have an orange plug. Very difficult to see or acess without removing cooler and turbo pipes.

You need to drain coolant also before you replace sensor