I am getting a P0128 code, which means that the computer has detected that the truck doesnt reach the proper temp. in a certain amount of time. The truck has new thermosthat that has been in for a few months, stock temp. I have the factory mechanical fan, and it spins when the truck is off so it isn't locked, the coolent is at the proper level as well. I have read that various sensors can also cause it to throw the code. My temp gauge goes up to where it normally always has in the right amount of time. If anyone else has any ideas, or experienced this then any help is appreicated.

Thanks