Oil Pressure Low
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The IPC illuminates the OIL PRESSURE LOW message in the DIC when the PCM detects a low oil pressure condition with the signal circuit low. The IPC receives a class 2 message from the PCM requesting illumination.