Change Oil Soon
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora and 2001 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The DIC displays the CHANGE OIL SOON 3 message when the powertrain control module (PCM) determines that the engine oil life is less than 11 percent. The DIC receives a class 2 message from the PCM. After the oil is changed, perform the engine oil monitor reset procedure. Refer to GM Oil Life System - Resetting in Maintenance and Lubrication.