Oil supply

The oil condition sensor reports the engine oil level and engine oil quality back to the DME control unit. A temperature sensor in the oil condition sensor indicates the engine oil temperature. The engine oil temperature is used together with the coolant temperature to calculate the engine temperature.

The oil pressure is indicated by the oil-pressure switch.

The oil level is also measured for the electronic oil level check. The 2nd capacitor in the upper part of the oil condition sensor registers the oil level. The capacitor is at the same level as the oil level in the oil sump.

As the oil level falls, the capacitance of the capacitor falls. The electronic evaluation unit creates a digital signal from this. The DME then calculates the engine oil level.

The DME control unit activates the warning and indicator lamp in the instrument cluster via the PT-CAN (red: oil pressure low; yellow: oil level low).

Electronic oil level check:

The dipstick now has a black handle. The engine oil level is measured by the oil condition sensor.

The measured value is displayed in the Central Information Display (CID).

The signal from the oil condition sensor is evaluated in the DME. Besides the oil level, the thermal oil level sensor also indicates the engine oil temperature.

Condition Based Service:

In addition, the engine oil quality is measured for the Condition Based Service (CBS).

The electrical material properties of the engine oil change as the engine oil wears and ages. The changed electrical properties of the engine oil (dielectrics) cause the capacity of the capacitor in the oil condition sensor to change.

The electronic evaluation unit converts the measured capacity into a digital signal.

The digital sensor signal is transmitted to the DME as a statement about the condition of the engine oil.

The DME uses this to calculate the next engine oil change as part of Condition Based Service (CBS).