2001 Buick Century Low Coolant Light

Hey Guys, I’m stumped.
Replaced sensor, light stays on.
Removed sensor, grounded the probe, light goes out.
Replaced antifreeze, bled system twice, no air or oil.
Getting desperate.
Removed and cleaned battery to body ground strap.
Removed and cleaned battery to engine ground strap.
Today found out there is no error code in the OBC but the light is still on.
Help Please!

Since the light goes out when you ground the sensor, I’d have to guess that the problem is not in the sensor or in the cooling system, or in general grounds - but in the wiring for the sensor itself.