HELP! Radiator fan always on

[Kobrins micra]

Our k11 nissan micra radiator fan is always running. We've had the car for 2 years but this problem only started a few days ago. The radiator fan will switch on a few minutes after startup even though it's only been idling and the engine is still cold. Think it might be a faulty sensor but not too sure

 

[.Maarten]

Id start with checking the temperature sensor. There are 2. 1 for the gauge and 1 for the ecu/fan. The 2 wire one is the ecu/fan one.