2015 Freightliner low antifreeze sensor

The low coolant sensor pretty much has to be located in the overflow tank. And I highly recommend adding the official approved coolant, not any old generic coolant, and certainly not Automatic Transmission Fluid, aka ATF.

Getting a low coolant warning may or may not signal a problem. It went off on our car the other day, and I had to add a half-gallon to reach the full mark. My wife, who is prone to panic when any car-related thing happens, was on it in a heart beat, demanding to know how much THAT was going to cost (how the hell should _I_ know?). Look, I said, it took 88,000 miles to lose the first half-gallon. If it takes another 88,000 miles to do it again, I won't care. If it loses that half-gallon over the next thousand miles, THEN I'll look into it.

Best to check with Freightliner (give them your VIN)to verify exactly what coolant they put in at the factory and use that. Then you KNOW that there will be no compatibility issues.

Yes it's on the overflow tank and ATF usually means Automatic Transmission Fluid. Buy two gallons so you will have a spare one of ELC.