Circuit/System Description

The engine oil level (EOL) sensor/switch is a normally closed switch that opens with a low engine oil level condition. With the ignition switch turned ON and the engine not running, the engine control module (ECM) detects a low signal voltage at the signal circuit of engine oil level sensor/switch. When the engine is running and the engine oil level is low, the ECM detects a high signal voltage at the signal circuit of the engine oil level sensor/switch. The ECM monitors the engine oil level switch signal circuit. When the ECM detects a high signal voltage on the engine oil level switch signal circuit, the ECM sends a GMLAN serial data message to the instrument panel cluster (IPC) requesting the low engine oil indicator ON.