Mazda CX-5 Manual page 629

Tab
Oil life (%)
Oil Change
Reset
Item
Displays the engine oil life until the oil replacement is due.
The wrench indication/indicator light in the instrument cluster
will be illuminated when remaining oil life distance is less
than 1,000 km (600 mile), or remaining days are less than 15
(whichever comes first).
Resets the remaining oil life to 100 %.
The system must be reset whenever replacing the engine oil.
Scheduled Maintenance
Explanation
Maintenance and Care
6-17