GMC 2002 Envoy Owner's Manual page 385

Scheduled Maintenance
Engine Oil Scheduled Maintenance
Change engine oil and filter as indicated by the GM
t
Oil Life System (or every 12 months, whichever
occurs first). Reset the system. The system will show
you when to change the oil
3,000 miles (5 000 km) and 12,000 miles (20 000 km)
since your last oil change. Under severe conditions, the
indicator may come on before 3,000 miles (5 000 km).
Never drive your vehicle more than 12,000 miles
(20 000 km) or 12 months without an oil and
filter change.
7-6
--
usually between
The system won't detect dust in the oil. So if you drive
in a dusty area, be sure to change your oil and filter
every 3,000 miles (5 000 km) or sooner if the CHANGE
ENG OIL light appears. Remember to reset the Oil
Life System when the oil and filter have been changed.
See "Oil Life System" in the Index for information
on resetting.
An Emission Control Service.