DTC P0520 Engine Oil Pressure Sensor/Switch Circuit Malfunction

In the realm of automotive diagnostics, understanding Diagnostic Trouble Code (DTC) P0520 is essential. This code indicates a potential issue with the Engine Oil Pressure Sensor or Switch Circuit. In this comprehensive post, we will delve into what DTC P0520 means, explore its possible causes, recognize symptoms, and learn how to diagnose and rectify this problem.

1. What Does P0520 Code Mean?

DTC P0520 signifies a malfunction within the Engine Oil Pressure Sensor or Switch Circuit. The engine’s oil pressure is a critical parameter for proper lubrication and operation. When the Engine Control Module (ECM) detects an issue or malfunction in the circuit responsible for monitoring oil pressure, it triggers this code.

2. What Are the Causes of DTC P0520?

Several factors can lead to the occurrence of DTC P0520:

  • Faulty Engine Oil Pressure Sensor/Switch: The sensor or switch itself may be damaged or malfunctioning, providing incorrect information to the ECM.
  • Wiring or Connector Issues: Damaged wiring or loose connectors within the sensor/switch circuit can disrupt its function and trigger this code.
  • Low Engine Oil Level: An insufficient amount of engine oil can result in reduced oil pressure and trigger DTC P0520.
  • Oil Pump Problems: Issues with the oil pump, such as wear or damage, can affect oil pressure and lead to this code.

3. What Are the Symptoms of DTC P0520?

Identifying the symptoms associated with DTC P0520 is crucial for diagnosis. Common signs of this code may include:

  • Check Engine Light: The check engine light will illuminate when DTC P0520 is detected.
  • Low Oil Pressure Warning: If the oil pressure is genuinely low, you may receive a warning on your dashboard or instrument cluster.
  • Engine Noise: Reduced oil pressure can result in unusual engine noises, such as knocking or tapping.
  • Reduced Engine Performance: The ECM may limit engine performance to prevent damage due to low oil pressure.

4. How to Diagnose DTC P0520?

To diagnose DTC P0520 accurately, follow these steps:

  • Utilize an OBD-II scanner to retrieve the trouble code and confirm the presence of DTC P0520.
  • Verify the engine’s oil level to ensure it is at the proper level. Top up if necessary.
  • Inspect the Engine Oil Pressure Sensor or Switch for visible damage or signs of malfunction. Replace it if necessary.
  • Check the wiring and connectors within the sensor/switch circuit for any visible damage, corrosion, or loose connections. Address any issues detected.
  • If no other issues are found, perform an oil pressure test to determine if the engine is generating adequate oil pressure.

5. How to Fix DTC P0520 Problem?

Once the issue affecting the Engine Oil Pressure Sensor or Switch Circuit and causing DTC P0520 has been identified, it is essential to address it effectively. Here’s what to do:

  • Replace the Engine Oil Pressure Sensor or Switch if it is damaged or found to be malfunctioning, ensuring it can provide accurate oil pressure information to the ECM.
  • Repair or replace damaged wiring and connectors within the sensor/switch circuit.
  • If the engine’s oil level was low, top it up to the proper level.
  • If the oil pressure test indicates low oil pressure, investigate and address potential causes such as a malfunctioning oil pump.
  • Clear the trouble code using your OBD-II scanner to reset the check engine light after completing the necessary repairs.


DTC P0520, indicating an Engine Oil Pressure Sensor or Switch Circuit malfunction, should be addressed promptly to ensure proper engine lubrication and operation. Understanding the code’s meaning, recognizing symptoms, identifying potential causes, systematic diagnosis, and effective solutions are crucial for maintaining the vehicle’s engine health and reliability.