The engine oil level switch is a normally closed switch that opens when there is a low engine oil condition. When the switch is open, the engine control module (ECM) detects a high signal voltage input. During a low engine oil condition the ECM sends a serial data message to the instrument panel cluster (IPC) requesting illumination of the LOW OIL LEVEL message in the DIC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Ignition OFF, disconnect the harness connector at the engine oil level switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal B and ground.

⇒	If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Install a 3-amp fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Engine Oil Level Switch parameter is OK.

⇒	If not OK, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, test or replace the engine oil level switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.