The symbol that has the downward arrow pointing towards a water sqiggle is on, but I'm not showing a code. I figure it might be a dirty sensor or something. Any idea which one?

 

thats the low coolant sensor. I am about to change mine out. It is located just below the filler neck on the radiator. I believe I was quoted around $35.00 from Chevy dealer.

 

http://shbox.com/1/low_coolant.jpg

 

The low coolant level sensor is connected only to that little light. It has nothing to do with the PCM and will not set a code.

 

Be sure to check the radiator level, not the overflow tank.

 

OK...I checked the radiator and DAMN that stank!!!!!!! It was funky. I mean you could smell it 20 ft away!!!!! But the fluid level was OK. So I had it changed out, and the light is still on.

Is the sensor just messed up?

 

Most likely the sensor is dirty. A lot of people, including me, just unplug it. If you take the battery out, you'll see it sticking out of the side of the radiator. Just remember to check the coolant level from time to time.

Sometimes you can clean the sensor and it'll work.