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P0520 – What Does It Mean and How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

P0520 is an OBD-II Code that refers to Engine Oil Pressure Sensor/Switch Circuit Malfunction

Meaning

A P0520 code is a generic diagnostic trouble code that occurs when the PCM/ECM receives a signal indicating the reading from the oil pressure sensor differs from the manufacturer’s specification. The oil pressure of a car is extremely important to the longevity of its internal combustion engine.

It transmits information regarding real oil pressure readings to the PCM via a reference voltage. When the engine’s control module detects an oil pressure level that is outside of typical ranges, it sets code P0520.

Causes

Common causes for this code include:

  • In the circuit, there is an excessive amount of resistance
  • Chain tensioners failure due to mechanical causes
  • An oil pressure problem, for example, a low oil pressure condition
  • Oil pressure sensor has malfunctioned
  • Using the incorrect engine
  • Oil pump or relief valve failure
  • Damaged PCM (Rare)

Symptoms

The symptoms of a P0520 code are:

  • Illuminated Check Engine Light
  • Oil pressure gage indicates a abnormal reading
  • Oil pressure indicator lamp illuminated

Also read: How to Fix Low Oil Pressure at Idle?

Diagnosis

To diagnose a P0520 DTC code, a technician would:

  1. Scan for codes in the ECM and look at the freeze frame data for failure.
  2. Visually inspect the engine for any signs of leaks.
  3. Check the oil level and condition.
  4. Test the oil pressure with a mechanical gauge.
  5. With a multimeter, test the voltage at the oil pressure sensor connector to see if it’s within factory specifications.

Common mistakes

The following are some of the most common mistakes that a technician may make when diagnosing a P0520 code:

  • Not thoroughly inspecting all the wiring and connectors.
  • Not checking the oil pressure with a mechanical gauge to verify the complaint.
  • Replacing an oil pressure sensor without first making sure there is no physical problem with the engine that would cause low oil pressure.

How serious is this?

A P0520 code is considered serious because it can indicate a problem with the engine’s oil pressure. If not addressed, this can lead to engine damage or failure.

What repairs can fix the code?

The following are solutions that may fix this problem:

  • Changing the oil pressure sensor
  • Repairing the oil pressure sensor wiring
  • Replacing the engine oil and filter

Related codes

A P0520 is related to and may be accompanied by the following codes:

P0521 – Engine Oil Pressure Sensor/Switch Circuit Range/Performance

P0522 – Engine Oil Pressure Sensor/Switch Circuit Low Voltage

P0523 – Engine Oil Pressure Sensor/Switch Circuit High Voltage

P0172 – Fuel Trim System Rich Bank 1

P0175 – Fuel Trim System Rich Bank 2

Conclusion

In conclusion, the P0520 code is a diagnostic trouble code that refers to a problem with the engine’s oil pressure. The code is serious because it can indicate a problem that may lead to engine damage or failure if not addressed. To fix the problem, a technician may need to change the oil pressure sensor, repair the oil pressure sensor wiring, or replace the engine oil and filter.