below regulated operating temp

[MikesTB]

My check engine light has been on for a while for coolant temp below regulated operating temp. Its not overheating so I don't worry too much but it is annoying I cleared the code several times some times the light will come right back on and sometimes it won't until the next day. The other day it seemed like it came back on it may have been coincidence any ideas?

 

[C-ya]

I'm sure someone else will chime in, too, but that usually means your thermostat is bad. Most folks change the temp sensor while they're there. If you continue to run cool, you can damage your catalytic converter.

 

[Matt]

Your mileage will suck too. Change them out and be done with it.

 

[v7guy]

Yeah, it's must likely the thermostat, up until 2006 the temp sensor is right by the thermostat so most people tend to change the temp sensor and thermostat at the same time.
you'll also see reduced gas mileage as well as the possibility of fouling the 02 sensor and ruining the cat.

you should take care of it as soon as is feasible