Oil Level Sensor: Description and Operation

The oil level switch is an assembly containing a reed switch and magnetic float. When the oil level is normal, the float rests near the reed switch, causing the switch to close. When the oil level is low, the float rests away from the reed switch causing the contacts to open.

The oil level switch is mounted in the engine oil pan. The oil level switch supplies a ground signal to the PCM when the engine oil level is above a specific level. If the engine oil level falls below this level, the oil level switch opens and the PCM sends a signal through UART serial data to the Instrument Panel Cluster (IPC) to illuminate the Check Oil telltale lamp.