Low Oil Pressure Warning (Medium Chime)

With the engine running the PCM connector C2 terminal 57 is grounded by the engine oil pressure switch.

If the engine oil pressure drops below approximately 20.5 kPa (3 psi), the engine oil pressure switch opens. The PCM detects this voltage. If the engine is running, the PCM sends a Class 2 serial data line message.

The IPC receives this message and illuminates the STOP ENGINE-LOW OIL PRESSURE message. A Class 2 message is sent requesting that the IRC turn ON the medium chime.