coolant sensor..

[JessDUB]

does anyone know if these are known to go bad? because i heard they do..

my cluster always has this big STOP thing on my lights, and says ''check coolant level'' flashing.... its NEVER LOW... and everytime i take it to the dealership (5 times already) the work order always says ''topped off coolant''.

last time i took it there, they said my radiator was cracked and my water pump was bad. (at 30,xxx mi.. which i think is strange) so they replaced both... and never did anything about the sensor. i suggested it may be bad.. still no luck.

anyone know what else it could be? or if it really is the sensor??