'Almost immediately" is the question.
If it is at the bottom with the key on (engine cold), then goes up quickly & holds it's position afterwards, probably normal.
These sense temperature B4 the coolant heats up, because of the "cylinder head temp sensor" mentioned earlier. So it shows warm B4 you'll get heat on a cold day.
"Odo Trick" - where you hold the trip button while turning it on, then page thru functions by pressing the button - this will get you to a digital reading for actual temperature. If it matches outside temp. when cold, then goes up to a normal engine temp while running, all is OK!
Check it B4 trying parts...