coolant sensor

[98 Jeep]

I keep getting this warning. I added a anti-freeze additive and a little water and it was OK for a few weeks but the warning is back. I probably have a leak somewhere but where?

 

[extra-medium]

check you hoses and connections. check your oil to make sure you haven't blown a head gasket, and check your freeze plugs to make sure they aren't leaking.

 

[98 Jeep]

check you hoses and connections. check your oil to make sure you haven't blown a head gasket, and check your freeze plugs to make sure they aren't leaking.

It's going in the shop tomorrow, hopefully it won't be too bad. I checked the oil, it was fine. What are freeze plugs, that's probably where the leak is. Is it a bad thing when this censor goes?