Buick 2003 LeSabre Owner's Manual page 269

When to Change Engine Oil (Vehicles
with the GM Oil Life SystemTM)
If so equipped, your vehicle has a computer system that
lets you know when to change the engine oil and
filter. This is based on engine revolutions and engine
temperature, and not on mileage. Based on driving
conditions, the mileage at which an oil change will be
indicated can vary considerably. For the oil life system to
work properly, you must reset the system every time
the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is necessary.
A CHANGE ENGINE OIL SOON message will come on.
Change your oil as soon as possible within the next two
times you stop for fuel. It is possible that, if you are driving
under the best conditions, the oil life system may not
indicate that an oil change 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. It is also important to check your oil regularly and
keep it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Oil Life System
The GM Oil Life SystemTM calculates when to change
your engine oil and filter based on vehicle use.
Anytime your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE ENGINE OIL SOON message being
turned on, reset the system.
To reset the Oil Life System, do the following:
1. Display the OIL LIFE INDEX on the DIC.
2. Press and hold the RESET button on the DIC for
more than five seconds. The oil life will change
to 100%.
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