Honda FourTrax Rancher TRX420FE1 2019 Owner's Manual page 43

Reset the meters after each scheduled maintenance.
To reset the maintenance tripmeter and the maintenance hour
meter, press and hold the mode button and turn the ignition switch
to ON ( I ). Continue to hold the mode button, the maintenance
minder indicator will light up, and after 2 seconds will flash twice,
the maintenance minder indicator is reset.
Also the maintenance tripmeter and maintenance hour meter will
reset.
Maintenance Minder Indicators:
Initial Maintenance
Appears at 100 miles (150 km) or 20 operating hours,
whichever comes first.
Regular Maintenance Interval 1
Appears 600 miles (1,000 km) or 100 operating hours
after the Initial Maintenance or Regular Maintenance
Interval 2 is performed and maintenance minder is
reset, whichever comes first in the maintenance
schedule.
Regular Maintenance Interval 2
Appears 600 miles (1,000 km) or 100 operating hours
after Regular Maintenance Interval 1 is performed and
maintenance minder is reset, whichever comes first in
the maintenance schedule.
If the maintenance is done before the setting interval, be sure to
reset the meters after the maintenance.
Indicators & Displays
Instruments & Controls 33