Oil Life Index Reset
WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Oil life index needs to be reset when powertrain control module is replaced.
Turn ignition on. Press the SELECT button on Driver Information Center (DIC) until the OIL LIFE % is displayed. Press RESET and hold for five seconds. OIL LIFE 100% will appear and then when the button is released OIL LIFE 100% will be displayed. The engine oil life monitor is now reset. Turn ignition off.