So i was completing my 3 hour trip home and about 10 miles from my house my check engine light comes on. I read the code using my edge and it said that the "coolant temperature less than thermostat regulating temperature". According to my edge my truck was running at about 176F when the light came on. So my first question is what temperature are our thermostats rated at? Also has anyone had this problem? Im thinking perhaps the thermostat is stuck in the open position.

2004 4.6
Ambient Temp was approximately 55F

 

The 4.6 should have a 195 degree thermostat like the 5.4 and I would also think it is stuck in the open position.

 

If thats the case there is definantly something going on. Gonna take out the old thermostat and see if its stuck open.