Circuit/System Description
WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
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.