why does my low coolent light come on after the car is at temp for a little while and the coolent isnt low?

Hello, if your low coolant light comes on and you have verified the coolant level is not low, then the sensor may be providing erroneous information or there could be a wiring concern present. Since the concern is happening after the engine has been running, it could be that the coolant level is actually low once running. Ensure this is not the case before wasting time testing.

Check coolant level in the radiator itself when engine is ‘ COLD’ by removing radiator cap.. IF coolant level is full then the coolant level sensor is suspect. The coolant level sensor is located on passenger side of radiator just behind the metal transmission fluid cooler line - it is difficult to access - highly recommend professional *hands-on* assistance. These radiator mounted sensors have indeed been problematic for GM vehicles. Good luck!

How did you verify the coolant is not low? Did you look at the reservoir line and saw that it was full? When you first start up your car from cold this is when the low coolant sensor is the most accurate. Don't look at the overfill reservoir after getting the low coolant light, wait for the car to cool and then open the radiator cap itself and shine a light into the radiator neck. The coolant should be visible from looking down into the opening. If it needs coolant pour some in. If you fill it up and the light comes on it is likely you are losing coolant through a leak in the system. Either a hose is leaking or somewhere around the intake it could be leaking and burning off.