With low oil pressure, the engine oil pressure (EOP) switch closes, and the signal circuit is low. With oil pressure above 4.5 psi, the EOP switch opens, and the signal circuit is high. The powertrain control module (PCM) monitors the oil pressure switch signal circuit, and sends a class 2 message to the instrument panel cluster (IPC), indicating the switch status.

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Ignition OFF, disconnect the EOP switch.
2. Ignition ON, verify the scan tool Engine Oil Pressure Switch parameter is Ok.

⇒	If not Ok, test the signal circuit of the EOP switch for a short to ground. If the circuit tests normal replace the PCM.

3. Ignition ON, perform the lamp test with the scan tool to turn the engine oil pressure indicator OFF.

⇒	If the engine oil pressure indicator does not turn OFF, replace the IPC.

4. If all circuits test normal, test or replace the EOP switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.