I got a 98 z28 recently my low coolant light went on but, nothing is wrong. I checked coolant,coolant level, radiator,stat,and hoses...everything is fine! My friend has a 99 ss and he has the exact same problem with nothing wrong on his car either. It has to be the C.T.S but i was wondering if maybe theres other maros with the same problem. Its possible that there could be a bulliten out at the dealership for this problem. What do you guys think?

 

Coolant level sensor is bad / going bad. It's located on the radiator below the cap. You can either replace it or just unplug it. Mine went bad a month or so ago, I unplugged it and do not plan on replacing it. Later model fbodies did not have the level sensor, so it looks like GM realized it wasn't really necessary.

 

Might as well have done that with the oil pressure and water temp sensors as well.