2003 Buick 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. 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%. 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. is possible that, if you are driving It under the best conditions, the oillife system may not indicate that an oil change is necessary for over a year. However, yourengine oil and filter must be changed at least once a year and this time the system must be at reset. It is also important to check your oil regularly and keep it at the proper level. 5-18