Low Oil Pressure
WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
The 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 body control module (BCM) receives a class 2 message requesting illumination from the PCM. The BCM sends a message requesting illumination to the IPC via the serial peripheral interface (SPI).