Oil Life/Oil Change: OIL LIFE displayed when the engine oil life remaining
is 10 percent and again when the engine oil life remaining is between 5%
and 1%. When oil life left reaches 0%, the OIL CHANGE message will be displayed.
An oil change is required whenever indicated by the display and according
to the recommended maintenance schedule. USE ONLY RECOMMENDED ENGINE OILS.
To reset the oil monitoring system to 100% after each oil change [approximately 5,000 miles (8,000 km) or 180 days] perform the following:
Note: This has been taken from the Ford Five Hundred owners manual.