P0520 Code: Meaning, Causes, Symptoms, & Fixing

The engine oil is very important for the efficient performance of the engine’s rotating parts. The oil ensures the smooth running of the rotating parts. The oil pressure sensor (switch) monitors the oil pressure. It sends this information to the powertrain control module (PCM). Your PCM uses this data to control the oil supply and many other functions. When the PCM detects an issue with the oil pressure sensor, it triggers the P0520 code. This article mainly explains the P0520 code causes, symptoms, and its fixing.

P0520 Code Definition

The P0520 code stands for “Engine Oil Pressure Sensor/Switch – Circuit Malfunction.”

What Does Code P0520 Mean?

The P0520 engine code indicates that your powertrain control module (PCM) detects an issue with the oil pressure sensor or oil pressure switch.

P0520 code

The engine oil is used to lubricate the moving parts of the vehicle. A sufficient supply of engine oil to all the vehicle’s moving parts is very important to achieve optimum performance. Your engine oil must have sufficient pressure to lubricate all the moving parts of the vehicle efficiently.

The oil pressure is a force that pushes the oil from the oil pan to all the moving parts. Your vehicle must have sufficient oil pressure to optimize the service life of all the moving parts of the IC engine.

Your vehicle contains an oil pressure sensor that measures the oil pressure. The main purpose of this sensor is to measure the engine oil pressure and sends this data to the PCM. The PCM utilizes the oil pressure sensor data to regulate the oil supply to the rotating parts and to ensure the efficient working of the engine.

The latest vehicle models usually contain an electronic control module that has a direct transmission of oil pressure.

Proper oil pressure creates an oil cushion between the internal rotating parts of the engine. It can either reduce or improve the resistance of the oil pressure sensor, and the PCM is capable of converting these changes into an accurate analysis of the actual oil pressure.

Causes of the P0520 Code

  • Bad oil pressure sensor
  • Damaged or corroded wires to the oil pressure switch/sensor
  • Loose connections to the oil pressure sensor
  • Use of incorrect (inappropriate viscosity) oil
  • Insufficient oil
  • Insufficient oil pressure due to dirty engine oil
  • Excessive resistance in the circuit
  • Contaminated engine oil
  • Mechanical failure of the chain tensioners 
  • Faulty parts, such as a bad relief valve or oil pump
  • Damaged or old oil filter
  • Oil leaks within the fuel lines 
  • Bad PCM/ECM

Symptoms of P0520 Code

  • Check engine light illumination
  • Excessive noise from the engine
  • The vehicle is hard to start or won’t start at all
  • A clear reduction in the engine performance
  • The limp mode is activated
  • Engine misfiring
  • The oil pressure warning light is flashing

How to diagnose the P0520 Code

  • Use an OBD-II scanner to scan all the trouble codes stored in the PCM memory.
  • Record the freeze data and analyze it to find the root cause of the problem. Clear the codes and perform a test drive.
  • If the P0520 code returns, then move forward for further inspection.
  • Inspect the engine oil level in the oil pan.
  • Inspect the wiring and connections to the oil pressure sensor for damage.
  • Inspect the oil filter for damage.
  • Inspect the oil pan for a leak.
  • Use a digital multimeter to test the voltage in the power and ground wires. Check the TSB to check the suggested values and compare these with the multimeter reading. If the voltage reading is off, it means that the power relay of your sensor is bad.
  • Check the oil pressure by using an oil pressure gauge.
  • Inspect the fuel lines for a leak.
  • Inspect the oil pressure sensor for damage or fault.
  • If everything is working fine, you may have PCM issues.

Common P0520 Code Diagnostic Mistakes

  • Not inspecting all the parts.
  • Replacing the oil pressure sensor before properly inspecting all the parts.
  • Changing the unnecessary parts.

How serious is the P0520 code?

The severity level of the P0520 code is moderate. This code indicates an issue with the oil pressure sensor of your vehicle. It may be very serious if the oil pressure is too high or too low than the requirements. Sufficient oil pressure is very important for the proper lubrication of the engine parts. Low oil pressure may reduce the engine’s performance or may cause damage to the engine parts.

FAQ Section

What is an Oil Pressure Sensor?

The oil pressure sensor is a mechanical device that is used to monitor the engine oil pressure and sends this data to the PCM.

What repairs can fix the P0520 code?

  • Adding more oil if needed
  • Changing the contaminated engine oil
  • Replacing the faulty oil filter
  • Cleaning the clogged oil filter
  • Fixing damaged or corroded oil pressure sensor wiring
  • Replacing the faulty oil pressure sensor
  • Fixing the fuel lines’ oil leaks

What are the symptoms of a bad oil pressure sensor?

When your oil pressure sensor goes bad, your vehicle produces one or more of the below-given symptoms:

  • Check engine light illumination
  • Too high or too low oil pressure
  • Wrong reading of the oil pressure gauge
  • Oil pressure light is illuminated

How to avoid triggering the P0520 code?

  • Use the best appropriate viscosity oil for your car. Always check the manufacturer’s manual to check the best oil for your vehicle.
  • Always replace your engine oil according to the manufacturer’s recommendation. 
  • You should always perform a routine oil check and ensure that your oil level is sufficient. 
  • Inspect your oil pressure sensor after a specific time interval. When your oil pressure sensor goes bad, immediately replace it.
  • Keep your engine clean.

Can I drive with the P0520 code?

Yes, you can drive with the P0520 code, but you shouldn’t drive for a long time with this code. This code indicates an issue with your oil pressure sensor. Sufficient oil pressure is very important to ensure the optimum performance of the engine. The vehicle’s rotating part may damage due to too low or too high oil pressure. Therefore, when your vehicle triggers this code, you should immediately fix it.

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