Engine Oil Level Sensors

The engine oil level sensors are used on different engines and they all work in a similar way. It is a simple float switch that is grounded when the engine oil level is okay. The Powertrain Control Module (PCM) checks the oil level switch circuit at start up. If the engine has been running, the PCM performs a test routine based on engine coolant temperature to ensure that the engine oil has drained back into the sump before checking the state of the engine oil level switch. If a temperature of the engine coolant is between 59°-284°F (15°-140°C), the PCM compares the engine coolant temperature at the last key OFF to the temperature at the current key ON . If the difference between the recorded temperature values is at least 54° (12°C), the PCM will test the engine oil level.