Engine Oil Level Warning Sensor

Check that continuity exists between terminals when the sensor-sensed temperature drops to 103°F (40°C) or less with the float down. See Fig 1.
Heat the switch to above 140°F (60°C) in an oil bath.
Check that there is continuity between terminals with the switch ON (float down). See Fig 2.
Check that there is no continuity between terminals with the switch OFF (float up). If the operation is not as specified, replace the switch.

Fig 1: Inspecting Engine Oil Level Warning Sensor When Temperature Drops

Fig 2: Inspecting Engine Oil Level Warning Sensor When Temperature Rises