Where do i refill coolant? message reading low engine coolant.

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 ?

Is your refill cap on overflow or radiator? More info please

This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.
A code P0128 may mean that one or more of the following has happened:

• Low engine coolant level
• Leaking or stuck open thermostat
• Faulty cooling fan (running too much)
• Faulty coolant temperature (ECT) sensor
• Faulty intake air temperature (IAT) sensor

Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code:

• Verify coolant strength & level
• Verify proper cooling fan operation (check if it's running more than it should). Replace if necessary.
• Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
• Verify proper intake air temperature (IAT) sensor operation, replace if necessary.
• If the above items check out good, replace the thermostat

you have all ready replaced the thermostat with the proper temperature opening thermostat(hopefully) and coolant sensor, you say you have to refill the coolant every 2 weeks this indicates that you either have a coolant leak that needs to be checked out and repaired or you are burning coolant which indicates a possible head gasket problem which will have to be checked. a low coolant level will set this code as there is not enough coolant in the engine to get the engine to operating temperature and stay there. these last suggestions is where I would start to look.

If your vehicle's engine is running hot or over heating, the issue could be any number of things. First check the coolant level in the over flow tank. If the tank is dry, check the coolant level in the radiator, but do not take the cap off when the engine is hot - only when the engine is cold. If the coolant level is low, fill the radiator with 50/50 antifreeze. If the level was low, there may be leak in the cooling system; the radiator, a leaking hose, etc. Also f refill the over flow tank to where it indicate "cold".

Another possible issue could be that the thermostat is stuck closed, which would prevent the coolant from circulating, causing an over-heat problem.

The water pump could be bad.

If the vehicle is older, has some mileage on it, and it not been maintained, the radiator could be clogged with mineral deposits.

There's no one answer, so you'll need to have the cooling system inspected.

Was it the check engine light or the Low Coolant error message?

If the former, likely an emissions problem - coolant is unlikely to solve that.

Have the OBD codes read at an auto parts store, proceed accordingly.

The Low Coolant light sometimes takes some time to reset.

You did refill / recheck it with the engine COLD, didn't you?

Maybe a leaking head is allowing coolant into one or more cylinders. Time for a professional repair.

Sounds like sticking thermostat. Replace thermostat if you see no leaks anywhere else.
You need to drain out any bad coolant or water when you replace thermostat and refill with concentrated antifreeze until you have at least 50% antifreeze water ratio.
You have to bleed the engine with new antifreeze solution so there's no air. I always go to youtube and see how mechanics do each engine bleed. Search your car and engine and `coolant flush'. don-ohio

Most probably is a leak somewhere, the sensor in the reservoir picks up when the level is low as to prevent engine damage. I would get it checked out. when repairing the water leak they should automaticly replace the coolant so i would just top it up with normal tap water till then. be carefull the water can burn you, so only open the bottle once the car is cold.

sounds like you have an air pocket in the coling syutem, there is a bleed valve by the water pump, open it unitl you get no air only fluid. then top off radiator and then top off coolant reservoir. If air pocket developes again sounds like a blown head gasket which is common on this make and model engine..

Silly question, but have you looked inside the radiator? I asked becuse often coolant is checked by looking inside the coolant overflow reservoir. Sometimes the ovrflow reservoir will look like the coolant is normal, when it's low in the radiator.

Here's a link which will give you more info.


http://www.gminsidenews.com/forums/f53/low-coolant-sensor-location-53810/