2010 Sierra coolant level sensor

[ChevyChase]

2010 GMC Sierra coolant level display on dash stays on but coolant level is fine. I need to find the coolant level sensor I have checked in fill tank still cannot find sensor.

 

[ChevyChase]

Engine is 5.3....Any information on this coolant sensor issue would be appreciated. I've been trying to locate it a couple weeks now.