Low Coolant Light On
My GTP had a common problem that a lot of GM products suffer from. It was the low coolant light on when I was certain I had plenty of coolant. This is a fairly easy fix and it may even be a free fix.
Be sure car is cold when doing this, if the radiator is hot you will get severely burned!
First remove the three bolts that hold on the passenger side brace on.
Second remove the negative battery cable and then the positive cable.
Now remove the one bolt that holds the battery clamp down and remove the clamp.
Now pull the battery out, you may have to remove the fuse box cover.
The sensor is about 4 inches down from the radiator fill on the side of the radiator.
Keep a rag handy.
Now unplug the sensor and remove the U shaped spring clamp. Then pull the sensor straight out. It is held in by two o-rings which will give it a little resistance as it comes out.
Now plug the hole with your handy rag because coolant is now running out on you.
Once you remove the sensor clean the probe that is on the inside. I used carburetor cleaner and it worked fine.
Now put the retaining spring back on and push the sensor back into the radiator and reinstall battery (positive cable first then negative cable).
Put the fuse cover back on and the brace.
Top off coolant.
Fire the engine up and let it run until it reaches operating temperature and check for leaks.
Hopefully now the pesky add coolant light is off!