Intermittent overheating

My 2014 5.7 Tundra recently started overheating intermittently. The temperature gauge will wrap out and the text alarm will pop up on my dash. I pull over but I don't see signs of a hot engine - no smells, no excessive heat, no fluid on the ground, overflow tank level is normal.
I replaced the thermostat and the problem went away for a week or two, but now it's back. I'm going to try "burping" it and replacing the radiator cap, but I suspect it might be a bad sensor.
Does anybody know where the sensor is?

 

Things to check first
fluid level and that it is not super old, replace if needed, burp the system
thermostat and cap
fan clutch

this has some pics that will be helpful https://www.tundras.com/threads/ove...-then-returning-to-normal-temp-quickly.80284/