Oil Level Sensor, Function

Oil Level Sensor, Function




The engine oil levels in the oil level sensor (S43) and in the oil sump are balanced through the bore (c).
The bore (c) is opened or closed by a bimetal snap plate (8). The bimetal snap plate (8) opens from an engine oil temperature of 60 - 70 °C and closes at an engine oil temperature of 30 - 40 °C.
When the engine oil is changed, the oil level sensor (S43) is therefore filled through the vent bore (d).







The oil level is measured with a float (6) with ring magnet (7) and a contact (arrow).
The contact (arrow) is closed by the magnetic field of the ring magnet (7) depending on the position of the float (6).
The contact (arrow) is open when engine oil level is less than "min", and closed when engine oil level is greater than "min".
When contact (7) is closed, vehicle ground exists at the base plate in the instrument cluster and the indicator lamp (e.g. model 202: A1e12) does not come on.







If the engine oil level is not sufficient, the contact (arrow) opens, the vehicle ground to base plate in the instrument cluster is interrupted and the indicator light (A1e12) comes on after a time delay of 60 seconds.
The time delay of about 60 seconds prevents the indicator light (A1e12) coming on if the car is accelerated or braked sharply or when cornering.
The indicator light (A1e12) also comes on when the key is in position 2 as a check function.