Low Oil Pressure
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The Instrument Panel Cluster (IPC) illuminates the engine oil pressure indicator when the Powertrain Control Module (PCM) detects low engine oil pressure, and the signal circuit is low. The IPC receives a class 2 message requesting illumination from the PCM.