Buick 2005 Century - Manual (Page 310)

Scheduled Maintenance
When the CHANGE OIL SOON light comes on, it means
that service is required for your vehicle. Have your
vehicle serviced as soon as possible within the next
600 miles (1 000 km). It is possible that, if you are
driving under the best conditions, the engine oil life
system may not indicate that vehicle service is
necessary for over a year. However, your engine oil
and filter must be changed at least once a year and
at this time the system must be reset. Your GM
Goodwrench dealer has GM-trained service technicians
who will perform this work using genuine GM parts
and reset the system.
If the engine oil life system is ever reset accidentally,
you must service your vehicle within 3,000 miles
(5 000 km) since your last service. Remember to reset
the oil life system whenever the oil is changed. See
Engine Oil Life System on page 5-16 for information on
the Engine Oil Life System and resetting the system.
When the CHANGE OIL SOON light appears, certain
services, checks and inspections are required.
Required services are described in the following for
“Maintenance
I ” and “Maintenance II .” Generally, it is
recommended that your first service be Maintenance I ,
your second service be Maintenance II and that you
alternate Maintenance I and Maintenance II thereafter.
However, in some cases, Maintenance II may be
required more often.
Maintenance I — Use Maintenance I if the light comes
on within ten months since vehicle was purchased or
Maintenance
II was performed.
Maintenance II — Use Maintenance II if the previous
service performed was Maintenance I . Always use
Maintenance II whenever the light comes on ten months
or more since the last service or if the light has not
come on at all for one year.
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