How to Test BMW Oil Level Sensor with E-dipstick

BMW has eliminated the conventional dipstick for testing oil levels from under the hood, replacing it with an electronic sensor. This does not, however, minimize the importance of knowing about BMW oil level sensor test.

BMW motor vehicles are now equipped with an electronic e-dipstick. The engine oil sensor lights up and illuminates the dashboard if the oil level inside the car’s oil pan has dropped below the safe level.

This sensor light does not necessarily mean that your car is due for an oil change, as many new BMW owners mistakenly assume.

The light indicates or informs you that the vehicle is at least 1 quart/liter low on engine oil. The manufacturers of BMW cars want you to believe that you can drive for 15,000 miles before the need to change the engine oil arises.

Without enough oil pressure, an engine cannot lubricate itself. The dashboard oil sensor light only comes on when the engine suffers a drop in oil pressure.

If the low oil level sensor light comes on, what can you do? If your BMW is the newer model that doesn't come equipped with the conventional measuring stick, then you need to fill 1 liter/quart of oil.

Then recheck the E-dipstick oil level indicator located on the instrument cluster/ iDrive of your BMW.

How to Test BMW Oil Level Sensor:

New BMW models are equipped with a condition-based service monitor designed to help the owner care for their cars on schedule.

When you just want to ensure that your vehicle is good to go, begin by checking the status of the BMW oil light located on the dashboard.

If you see an orange-yellow oil light, that means that your BMW needs more motor oil.

However, a red oil light tells you that your oil pressure is getting low, and immediate action is required.

But how do you check the BMW oil level sensor? Follow these five steps:

Step 1: Remove the sensor’s electrical connector

Do this by pressing the button that disengages the lock and pull to remove it. This renders the BMW oil level sensor inactive.

Step 2: Test the resistance

Once you turn off the engine, connect one lead of the meter to the sensor warning light terminal. Touch the other lead to the sensor housing/casing.

On a well-functioning sensor, you should get 0 ohms reading. Connect the terminal lead for the sending unit and the housing. That ought to read as an open circuit.

Step 3: Start the vehicle

Turn on the ignition switch for the next testing phase.

Step 4: Check terminal resistance

Recheck the terminal resistance with the engine running. If there is oil pressure, the reading should be infinity on the switch terminal to indicate an open circuit.

Depending on the operating speed, oil viscosity, and temperature, the sending unit should be reading in the 30-55 ohm range.

Step 5: Replace the defective sensor

For a proper BMW oil level sensor reset or replacement, first switch off the car. If the oil sensor returns to the specified settings on the manual, reattach the connector.

If the oil sensor does not reset to the proper settings that means you have a defective instrument that should be replaced.

How Does an Oil Level Sensor Work?

Standard oil sensors function by displaying a warning signal whenever the oil pressure falls outside or below the set oil range.

Oil sensors are used in industrial and automotive applications to send or gather valuable information. An oil level sensor is an oil level controller or oil float that opens and closes circuits as the oil levels fall or rise.

These closing and opening circuits can be automatically used to turn different oil pumps on or off.

Other oil level sensors employ magnetic reed switches to measure oil levels and, when necessary, automatically turn on or off the oil pump.

Some of the earlier applications only monitored if the oil level in an engine was low using a switch attached to a float.

The oil pressure sensor would just trigger a light or message in the instrument cluster. They only measured oil levels when the engine was off.

Modern applications, such as the BMW oil level sensor, measure the level differently. You do not have to turn off the engine as the oil level can still be measured with your engine running.

Some oil sensors utilize the electrical resistance method that functions similar to a mass airflow sensor. The resistivity of the oil sensor changes as less of the sensor gets covered by oil.

Testing Oil level Sensor by Using Multi-meter

A multi-meter is an instrument used to test circuits. The electrical device measures current, voltage, and continuity, hence multi-meter. It is also a vital device for troubleshooting.

Testing for continuity and measuring current/voltage/resistance can help identify and locate problems when a device or circuit malfunctions.

A multi-meter can also be used to test whether the oil lever sensor is working well.

Step 1

With the engine off, insert the key into the ignition and turn it to the accessory setting.

Step 2

Look at the oil gauge located on your dashboard. Identify the wire that connects to the sending unit and unplug it if the indicator is at zero.

Step 3

Next, disconnect the wires that connect to the pressure switch. You can do this by pulling off the wire connectors to the switch terminals.

Step 4

Set the multi-meter to test and probe for resistance.

Step 5

The tester should read 0 or close to 0 (ohms) to indicate no resistance.

FAQs

1. Where is the oil level sensor?

The sensor is positioned inside the BMW’s oil pan, and its primary role is to gauge the amount of oil inside the oil pan.

2. How accurate is the BMW oil level sensor?

If the oil level reads normal, the main suspect is likely to be a defective oil sensor. The oil sensor can fail in two ways; it can leak oil or fail electrically.

An electric malfunction can be identified as a yellow oil warning light on the BMW’s instrument panel.

3. How do you check the oil on a BMW without a dipstick?

The best way of checking is through the sensor lights on your car's dashboard as it responds to the E-Dipstick.

4. Can you clean an oil level sensor?

Although an oil sensor can bad, the good news is that you can clean the filter screen easily with a brake cleaner using low air pressure.

However, it’s best to replace a defective sensor.

5. Will low oil cause BMW not to start?

When the warning light comes on, it does not mean your BMW will not start. It simply warns you that your engine is running low on oil.

Conclusion

A car requires motor oil to perform properly. Although your BMW may look like any other car on the road, it now comes with many electronic components and features.

Knowing how and when to check your vehicle’s oil is essential. However, the steps to take in a BMW might differ from what most car owners are used to.

When in doubt, consult the manufacturer's manual. Have a qualified professional assess the sensor for you.

BMW cars are expensive, and a wrong diagnostic could be costly. Sensors have now gone electronic. No longer are traditional oil dipsticks being used in some motor vehicle models such as the latest BMWs.

The ultimate question is, how does a BMW oil level sensor work? Is it functioning optimally?

The best way of testing whether your BMW sensor is functioning well is through the sensor warning lights.

When the warning light comes on yet the oil levels are normal, and the engine is running quietly/smoothly, then most likely your oil pressure sensor is bad or not functioning well.