This is a sensor to tell you it's time to change your oil. Some are triggered at 3000 miles, some at 5000, depends on the year. check your owner's manual to find out how to reset it. It usually involves a number of steps.
The 2019 navigator as far as I know uses PROX remotes (keyless entry and keyless start) with a fcc id of: M3N-A2C940780
The 2004 navigator uses a completely different style of keyless entry remote with a fcc id typically of CWTWB1U331 or CWTWB1U511.
If you want to try, go to your 2004 Navigator.
Insert key and turn ignition ON to OFF 8 times ending ...