LOW COOLANT LIGHT STAYS ON ALL THE TIME EVEN WHEN SYSTEM IS FULL.

Your overflow tank(aka coolant recovery reservoir) is low on coolant. The coolant expands when warm and raises the level in the tank, which turns off your light. Top off the reservoir (when cool) to the "Full Cold" line. If you have to keep adding on a regular basis, then you have a leak somewhere in your cooling system, could even be the reservoir itself.

make sure you are still full it could also be air in the system if your car is getting temp is getting hotter than usual it is probably air in the system it could also be a stuck sensor.

Check that the wiring and terminals to the sender unit are not broken or dirty. If they are good maybe the sender unit it self is not working.

In most newer chevys, the coolant reservoir is part of the pressurized system. Rather than just holding overflow coolant and relying on the radiator pressure cap to draw from and expel to the reservoir, it is an active part of the cooling system. On these systems, there is a coolant level switch in the reservoir. This will activate if the level in the reservoir gets below a certain point. So it is possible to have a full radiator and still get a low coolant light. Be advised that as the reservoir ages and get stained, it is not uncommon for the low coolant sensor to give false indications of low coolant.

You may have to reset it by putting in a code. You can find the code in your owners manual. In our Grand Am we have to reset the Check Oil light after we change the oil. For the oil light it is something like press the gas peddle in 5 times within 30 seconds....something like that. Good luck

i had same problem with my lumina it ended up having a blown head gasket. do a compression check and look for a low cylinder on the outside or twq cylinders next to each other that are low.if they are low it indicates a blown gasket. hope this helps

Most of the time it is located in the reservoir.

if rad full then its the sensor in the header tank

get a scan tool for that car i believe a tech 2 scanner will work adn clear the codes, if it comes back on then you are going to have to do some more digging

Check you coolant resevoir. The low coolant switch is located in the resevoir so if it is low on coolant there, the light will come on. If it is full, it could be that the switch is stuck due to gunk build up in the resevoir. Hope this helps you out