Oil Change Reminder Lamp: Description and Operation

Message Center


Oil Change Minder

The message center provides an oil change minder to inform the driver that an oil change is required. The duration of the interval between oil changes is calculated in the PCM (Powertrain Control Module) and varies due to driving conditions. The PCM (Powertrain Control Module) assumes a base mileage of 16,090 km (10,000 mi) or 1 year for normal driving. However, this number is adjusted down for conditions such as high engine temperature, high engine RPM (Revolutions Per Minute), use of flex fuel and possibly low oil level. The PCM (Powertrain Control Module) calculates and provides an engine oil life percent message to the IPC (Instrument Panel Cluster). The IPC (Instrument Panel Cluster) further converts the remaining oil life using the driver's configured oil life start value and displays the oil life percentage, indicating the remaining oil life. The oil change minder can be reset at any time by the driver.


Low Oil Pressure Message Center Warning Indicator

The engine oil pressure switch is hardwired to the PCM (Powertrain Control Module). The PCM (Powertrain Control Module) provides the engine oil pressure status and engine RPM (Revolutions Per Minute) data to the IPC (Instrument Panel Cluster) over the HS-CAN (High Speed Controller Area Network) communication bus. The IPC (Instrument Panel Cluster) requires engine RPM (Revolutions Per Minute) above 500 RPM (Revolutions Per Minute) before the message center displays the low oil pressure message center indicator.

The PCM (Powertrain Control Module) provides a reference voltage to the engine oil pressure switch when the ignition is in RUN. With the engine running and low or no oil pressure, the engine oil pressure switch remains open. The PCM (Powertrain Control Module) detects no change in the reference voltage and provides the IPC (Instrument Panel Cluster) a request to illuminate the low oil pressure warning indicator. With the engine running and sufficient oil pressure, the engine oil pressure switch closes, pulling the reference voltage low. The PCM (Powertrain Control Module) detects the low reference voltage and provides the IPC (Instrument Panel Cluster) a request to turn off the low oil pressure warning indicator.

The engine oil pressure switch is hardwired to the PCM (Powertrain Control Module). The IPC (Instrument Panel Cluster) receives the oil pressure warning message and the engine RPM (Revolutions Per Minute) message from the PCM (Powertrain Control Module). With the KOEO (Key ON Engine OFF), the IPC (Instrument Panel Cluster) does not display the low oil pressure message center warning indicator until the engine is started and it receives the engine RPM (Revolutions Per Minute) message.