Check Oil Level
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The IPC illuminates the CHECK OIL LEVEL message in the driver information center (DIC) when the powertrain control module (PCM) detects a low engine oil level condition. The PCM only monitors the oil level switch signal circuit for a brief period between key on and ignition crank. The IPC receives a class 2 message from the PCM requesting illumination.