P0521 Code: Meaning, Causes, Symptoms and Fixing

Your vehicle contains the main computer (most usually a powertrain control module) that controls the functionality of different parts. The powertrain control module (PCM) triggers a specific trouble code when it detects an issue with a specific part. When your oil pressure sensor does perform according to the requirements, your PCM triggers the P0521 code. This article mainly explains the P0521 code symptoms, its causes, and how to fix it.

P0521 Code Definition

The P0521 code stands for “Engine Oil Pressure Sensor/Switch Range/Performance.” 

What does the P0521 Code mean?

The P0521 code indicates that your PCM detects an issue with the engine oil pressure or oil pressure gauge readings or performance.

P0521 code

The latest vehicles contain a PCM/ECM. It uses to control the functionality of the engine sensors and some other electronic parts. The PCM gets data from different sensors and utilizes this data to ensure the optimum performance of the engine.

The engine oil pressure is one of the most important engine sensors. This sensor measures how much mechanical oil pressure is present inside the engine and sends this data to the PCM.

The PCM of the vehicle utilizes this data and tells the driver about the oil pressure in one of two methods. Some vehicle models have a gauge on the dashboard to indicate the oil pressure, while some vehicles contain a warning light that starts illuminating when the oil pressure is less or more than the specified limit.  

When your PCM notices a problem with the performance of the engine oil pressure sensor, it triggers the P0521 code.

Causes of the P0521 Code

  • Clogged oil lines
  • Damaged or bad oil pressure sensor
  • Bad oil pressure switch
  • Using the wrong viscosity engine oil
  • Bad or clogged oil filters
  • Inadequate engine oil
  • Damaged electrical connections and wires to the oil pressure sensor
  • Contaminated oil
  • Unnecessary mechanical wear in the engine components, such as the oil pressure relief valve and oil pump

Symptoms of the P0521 Code

  • Check engine light is flashing
  • Misfiring
  • Hard to start the engine, or the engine won’t start at all
  • Engine stalling
  • Engine noise, such as ticking, thudding, knocking, or rumbling
  • The oil pressure gauge reading is too low or too high

How to diagnose the P0521 Code?

  • Use an OBD-II scanner to extract all the codes stored in the PCM memory. Analyze the main problem by using the freeze data. Clear the PCM memory and perform a test drive. If the P0521 code returns, then move forward for further inspection.
  • Inspect the oil level in the oil pan.
  • Inspect the condition of the oil. Your oil must be contaminated free.
  • Inspect the fuel filters and drain plugs.
  • Check the oil pressure sensor wiring for damage.
  • Use an ohmmeter to check the voltage of the oil pressure sensor.
  • Inspect the oil pressure sensor for damage.

Common P0521 Code Diagnostic Mistakes

  • Replacing the oil pressure sensor without inspecting other parts.
  • Not clearing the powertrain control module storage after fixing the issue.

P0521 Code Repair Cost

The repair cost of code P0521 depends on the vehicle model and the parts that need to be repaired. To fix this code, you need to repair or replace one or more of the following parts:

Oil filter replacement$30 to $80
Oil replacement cost$15 to $70
Oil pan replacement$650 to $750
Oil pressure sensor replacement$120 to $150

FAQ Section

What is DTC P0521?

The P0521 code is triggered when the PCM monitors the voltage value of the engine oil pressure sensor as either higher or lower than the specified limit.

What repairs can fix the P0521 Code?

  • Replacing the dirty oil
  • Replacing the bad oil pressure sensor
  • Adding more oil if needed
  • Replacing the bad PCM
  • Changing the faulty or clogged oil filter

How serious is the P0521 Code?

The P0521 trouble code is considered a moderate trouble code. When your vehicle computer triggers this code, it means something is wrong with the engine oil pressure sensor. The proper working of the oil pressure sensor is very important. When your vehicle triggers the P0521 code, you shouldn’t drive your vehicle for a long period of time because driving with this code may damage your engine.

Can low oil cause the P0521 code?

Yes, a low oil level or contaminated oil is one of the most famous causes of the P0521 code.

How to reset an oil pressure sensor?

  • Insert the ignition key into the ignition switch and turn it to the on position without starting the engine.
  • Now gradually press the gas pedal 3 times in a row within ten seconds. This step resets your system.
  • Confirm the reset by turning the ignition switch off and then turn it on again.
Read More

Leave a Comment