Anti freeze loss

Sensor in the fill tank is probably bad .
LOW COOLANT
The IPC illuminates the LOW COOLANT indicator in the message center when the IPC detects a low coolant level condition from the PCM. The IPC receives a class 2 message from the PCM indicating the coolant level.
Coolant Level Control (If Equipped)
The engine cooling system contains an engine coolant level switch to alert the driver in the event of a coolant loss. The powertrain control module (PCM) sends out a coolant loss signal over the coolant level switch signal circuit. When the engine coolant level switch reads a low coolant level in the fill tank, the switch opens. The message center receives its power from engine wiring harness junction block on the battery positive voltage circuit. Ground is provided by the ground circuits via the body wiring harness junction block and the engine wiring harness junction block. The cluster receives the class 2 message from the PCM indicating Low Coolant and displays the LOW COOLANT LEVEL message on the driver information center (DIC).

Is the fill tank full ?

Check coolant level...may just be low on anti-freeze ...next check would be the thermostat...hope this helps.

Is it full of coolant if yes level sensor bad if not fill rad and overflow bottle to proper level and retest

If you added the green anti freeze to you system it will make the check coolent level light come on. Drain the system and use the extended life anti freeze and that will fix the problem.

If you are saying that it comes on now and then, and goes off, your may just need to add Anti-freeze/boil to the overflow tank. Does it come on when you're coming to a stop or going up or down a hill, if yes, add coolant to the overflow tank to bring it up to the correct level, not the radiator.

A small loss over a long period of time is acceptable, but constant refilling, indicates a leak either internally, with the coolant exiting through the exhaust, or one that you should see under your car occasionally. Sometimes you'll find your coolant leak in the floorboards if the heater core or hose leaks.

If your sensor comes on after driving a while & goes off as a result of adding coolant, then you'll probably need to pressure test the cooling system to identify where the coolant is going. Bad hose, seal, headgasket, head, etc.

Good luck !

The sensors get clogged with dirt and grime. Have to find a way to clean the sensor or replace it. As long as you have coolant and it goes off everything is fine. However you would never want to have a coolant leak and ignore the light. That would ruin your car.

it may only be a case of topping it off with anti-freeze depending on where you live in world,have anti-freeze checked for freezeing level. i recommend 20 degrees below 0 if alaska or that part of world,30 below0 if you top it off and light goes off, thats the problem. the overflow container has a sensor in it that makes the light come on to alert you that coolants low.you need to use the green antifreeze. if you have pets, clean up all spills as anti-freeze is deadly to animals and if consumed by children or adults deadly also. thank you for choosing fixya.com

Check the coolant resevoir. When the coolant level gets low, that will trigger the check engine sensor to come on. If the level is low, just add a little anti-freeze/water mix too it.

The coolant sensor liight come on when the Anti-freeze get low. Just top off the ant-freeze and the light will go out. It is norrmal for anti-freeze level to go down but slow. Toping off once or twice a year is ok but anymore then that you really should check for leaks. Low anti-freeze will cause over heating. Over heating can wreak an engine.

You need to fill the expansion tank and the radiator with 50/50 mix, it will level itself out. There is no quantity, just fill it up. About 2 gallons.