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Oil Pressure Sending Unit Explained

February 21, 2024 | Victor Lukasso

Several computerized components in a car make driving easier; one is the oil pressure-sending unit.

In this case, The Oil pressure sensor signals the driver if the car runs into an oil shortage.

If the oil pressure sending unit becomes faulty, the driver might not know about the pending problem, which could result in further damage.

In this article, you’ll learn the relevance of the oil-sending unit, its functions, and how to Fix a faulty oil pressure-sending unit.


What is the Oil Pressure Sending Unit?

The oil pressure sending unit is a mechanical component of a vehicle that monitors the flow of oil within the engine.

It sends signals regards the vehicle oil pressure to the driver using indicator lights.

The oil pressure gauge (sensor) and the warning light indicators (sensor) need data from the car’s electronic system to work correctly.

The oil pressure-sending unit also provides the automated system with the signals to interact with the gauge and dashboard warning light.

Therefore, if the oil transmitting unit malfunctions, the computerized system will get the incorrect signal or no signal, and it will then relay that signal to the meter and dashboard oil pressure warning light.

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Now, let’s briefly review the difference between the oil pressure switch and the sensor.

Oil Pressure Switch Vs. Oil Pressure Sensor

The two might look quite alike because they rely on the oil pressure sending unit for data, but there are a few differences.

The oil pressure switch turns the oil pressure warning light on your car’s check engine light if it detects low oil pressure.

Meanwhile, the oil pressure sensor is responsible for measuring and providing the pressure gauge with the correct pressure readings.

Symptoms of a Faulty Oil Pressure Sending Unit

The oil pressure-sending unit is an essential component of the car that needs frequent checks and attention for the proper functioning of the vehicle.

Here are a few symptoms you should watch out for to determine if an oil pressure sending unit is faulty.

  1. The Oil Pressure warning light will turn on
  2. Incorrect oil gauge readings
  3. Frequent blinking of the oil pressure warning light

The automatic illumination or blinking of the oil pressure warning light is one of the early signs of a faulty oil pressure transmitting unit. When the oil transmitting unit malfunctions, it activates the warning light and keeps the display on until the issue is fixed.

When you check the oil level, sometimes everything turns out fine. In that situation, it can be a brief warning that the oil transmitting unit is slowly degrading and requires rapid repair.

In addition, Have you ever noticed an oil pressure gauge on a car reading zero all day, even the next day? That it is; the oil pressure sending unit in the car is broken. The gauge may occasionally indicate less than or more than the accurate oil pressure.

It’s best to quickly find a fix to this problem to prevent further damage to your car.

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How to Fix a Faulty Oil Pressure Sending Unit?

Below are some fixes you can deploy to fix incorrect oil pressure readings on your pressure gauge.

  • Check your oil and perform an oil change if necessary
  • Replace the oil pressure switch
  • Change faulty oil pressure sensor/unit
  • Take your car to a mechanic for assistance.

Causes of Oil Pressure Sending Unit Failure

Below are some notable reasons a car’s oil pressure-sending unit will fail.

  1. Fault in the wiring harness of the oil pressure unit
  2. A worn-out plug
  3. A disconnected connection

How to Test an Oil Pressure Sending Unit

Here is a way to test a failing oil pressure sensor or unit.

  1. Insert the key into your vehicle and turn to accessories Mode
  2. Monitor the oil pressure gauge on the dashboard
  3. Check the oil pressure gauge on the car’s dashboard once the key is in the accessory position. Detach the wiring on the oil transmitting unit if the oil pressure indicator on the dashboard displays zero. If it shows up to 3, the oil-sending unit is damaged and needs to be replaced.
  4. Touch the loose wire against a metal.
  5. You can also take the wire cut from the oil-sending unit and touch it to the negative terminal of the car’s battery or another metal component.

After that, recheck; if the oil pressure indicator displays zero (zero), the oil sending unit is in a good state.

How to Replace a Faulty Oil pressure sending unit

Replacing a car’s oil pressure-sending unit will cost you a few bucks if you’re visiting an auto engineer, but here’s a guide you can lay your hands on if you’ll love to do it yourself.

Nevertheless, quickly resort to a mechanic to prevent further damage once you find a step complicating.

  • Make sure your car engine is cooled off
  • Disconnect the battery terminals to avoid shock
  • lose the wiring on the mechanical oil-sending unit
  • Use an oil pressure sending unit socket to loosen the oil sensor
  • Please get a new oil sensor unit and apply tape around it to curb leakage
  • Tighten the new oil pressure sensor unit carefully to avoid miss-threading
  • Reconnect the battery terminals and oil pressure sending unit wiring
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That’s it.

After everything has been done, start the car by putting in the key. Next, notice how the oil pressure gauge and warning light function on the dashboard. When they work correctly, you are ready to travel! If they don’t, you might have to repeat the procedure paying more attention this time.


Can I Drive with a faulty oil pressure sending unit?

A faulty Oil pressure sensor doesn’t necessarily mean your vehicle’s oil pressure is low.

However, it would be best to check your oil pressure manually to avoid damages that might come with low oil pressure.

Notwithstanding, you can fix the oil pressure sending unit to help you keep a check when your car runs into an oil pressure that’s lower than ideal.

What happens when an oil-sending unit fails?

If a car oil-sending unit fails, a car owner will receive a zero or wrong oil pressure reading on the gauge.

How to know a faulty Oil pressure sending unit

If your vehicle runs fine, your check engine light turns on, or the pressure gauge reads zero all day.

Are the oil pressure sensor and oil-sending unit the same thing?

Yes, the oil pressure sensor and the oil-sending unit refer to the same thing. Another term used to represent these two Is the oil pressure switch.

Is it easy to replace the oil sensor?

Yes, depending on the location of the oil sensor on your vehicle, it is easy to test and replace.


An insufficient oil pressure sending unit doesn’t mean your automotive will not function properly.

However, checking out this article’s causes, Symptoms, testing, and fixes will help you resolve a faulty Oil pressure sensor.

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Meet Victor Lukasso, the owner of V. Auto Basics. Through this blog, Victor Provides Insights on the latest tips, maintenance, repair, and techniques in the automotive world.