GM Service Manual Online
For 1990-2009 cars only

Object Number: 806876  Size: A1

This feature assists in determining when to change the engine oil and filter. Ion engine operating temperature, number of engine revolutions, and vehicle mileage. See Engine Oil for more information.

The "CHANGE OIL SOON" LIGHT should come on as a bulb check when you start the engine. This is normal. If this light stays on for about 30 seconds after you start the engine, it means there's less than 5 percent of the oil life left, and you should change the engine oil soon.

The system should usually indicate to change the oil and filter before 7, 500 miles (12 500 km). Never drive your vehicle more than 7,500 miles (12 500 km) or wait longer than 6 months to have the oil filter changed -- even if the "CHANGE OIL SOON" does not come on.

If you drive in a dusty area or in a high humidity climate or tow a trailer, you should change your oil and filter every 3,000 miles (5 000 km) or 3 months (whichever comes first) unless the "CHANGE OIL SOON" light indicates changing it sooner.

The system does not check how much oil you have, so you'll still have to check for that. To see how, see "Engine Oil" in the Index.

Each time you change your engine oil, the system must be rest. To find out how to do this, see "Resetting the Change Oil Soon Light" in the Index.

Always keep a written record of the mileage and date when you changed your oil.