Oil Life Index

Oil life index is calculated by the Powertrain Control Module (PCM) and sent to the Instrument Panel Cluster (IPC) via the Class 2 serial data bus. Oil life is displayed as "OIL LIFE INDEX NORMAL###%," where ### represents the approximate percentage of useful oil life remaining. The word " NORMAL" will be replaced with "CHANGE OIL" when the oil life index is less than 11%. This portion of the IPC will read ???? if there is a loss of PCM communications. After an oil change, the index can be reset by displaying the oil life index and than pressing the "RESET" button for approximately 5 seconds. when the value is reset, 100 will be displayed for the oil life index.