[RocketSurgeon]

I have an e90 and an F02 that are showing full oil level when I know they are both more than a quart low. Is this a known issue? I did an oil change on the e90, and only put in 5 quarts of the required 7, figuring I would use the dash reading to top up accurately. It did the calculation thing and read exactly at the max level.
Similar deal with the f02, it has a punctured oil cooler with oil EVERYWHERE, and it tells me there's plenty of oil to start it. These sensors have me a little concerned, since the only way to confirm the level is to clean catch it.

[diagnosiks]

Maybe this will help you somehow

The oil level sensor works on the principle of temperature measurement.
The current oil temperature is measured by the sensor. Then the sensor is shortly heated to a temperature above the current oil temperature.
After the heating is switched off by the ECU, so the oil level sensor is cooled by the engine oil again, and logically to the level of the current oil temperature. Due to the duration of the cooling time, the ECU calculates the actual oil level.
Simply cause the more is oil in the sump, the faster is the cooling time.
And the less oil is in the sump, the longer is the cooling time to the actual oil temperature.

But there is more to know.. There is almost always a bonnet contact installed, if an oil sensor is present. The reason is : If a low oil level is calculated by the ECU and then the hood is opened, the ECU assumes that the hood has been opened to fill up oil. If you then continue driving, the measurement and evaluation will start only after driving a certain number of miles/kilometers. The new refilled oil has a different temperature (lower one) and may otherwise lead to incorrect measurements.

Best Regards