What Is P0521 Code On Chevy Silverado & How To Fix It?

You will encounter a variety of mechanical errors while using your Chevy Silverado. These mechanical problems are expressed through different codes. P0521 is one of those codes.

The P0521 code indicates any problems with your truck’s Powertrain Control Module (PCM). You can identify the error code through some symptoms. 

Like other mechanical problems of automobiles, your truck encounters P0521 error code problems for several specific reasons. However, by taking appropriate steps, this error code can be avoided. 

In this article, we will discuss how to diagnose the P0521 error code and what method can be used to fix it.

What Does P0521 Code Means On Chevy Silverado?

The code P0521 means one or more problems related to your Chevy Silverado’s PCM. Every modern vehicle has a PCM system installed.

The PCM system is very important for your truck because it controls many sensors, electronic components and different types of controls at once. One of these is the oil pressure sensor which measures the amount of oil pressure in your truck’s engine. 

The sensor shows the information through the PCM of your truck. PCM sends you this information in two ways. One is that if your truck has a gauge on the dashboard, you can see how much oil pressure there is. 

The other is that if your car does not have a dashboard, you can understand it with the help of an indicator light.

The P0521 error code is detected if there is an unwanted problem with your truck’s PCM system. The main problem is that the oil pressure is sometimes high and sometimes low.

Symptoms Of Getting The P0521 Code On Chevy Silverado

Like your Chevy Silverado’s other problems, the P0521 error code has some specific visible symptoms which are mentioned below:

  • The check engine lights are on;
  • The oil pressure gauge is reading very high and low;
  • Oil pressure warning lights are on;
  • Having unwanted noise in the engine;
  • The engine is stalling.

If the above symptoms are observed in your truck, you can be sure of the P0521 error code.

The Causing Factors Of The Error Code P0521

Whether unintentional or due to your mistake, the P0521 error code has one or more reasons behind its detection on your Chevy Silverado. Because no problem is created automatically. Let’s find out the reasons why your truck is suffering from the P0521 error code.

  • Dirty and Improper Oil: Once the engine is full of oil and used for a long time, it becomes dirty. The code P0521 will be detected if you continue to drive the truck with that dirty oil. 

On the other hand, if you use unauthorized oil, it may be the cause of the error code.

  • Empty Crankcase: Check your truck’s engine. See if the crankcase is empty. If there is an empty crankcase or a small amount of oil, it may be the cause of the error code.
  • Low Oil Pressure: One of the reasons for the P0521 error code may be the low oil pressure in your Silverado’s engine. 

If the oil pressure warning light comes on or you get readings in the oil pressure gauge, you will understand that it is the arrival signal of the P0521 error code.

  • Faulty Oil Pressure Sensor: If your truck’s oil pressure sensor is faulty, it could be the cause of the P0521 error code. 

However, in this case, it would be wise to measure the oil first and check the wiring of the sensor.

  • Defective Oil Pressure Sensor Connection: Notice if the oil pressure sensor in your truck that is connected to it is open or shorted. 

If there is a problem with the connection of the sensor, it will not work and the P0521 error code will appear.

How Serious Is Code P0521 On Chevy Silverado?

As with any automobile-related problem, if the code P0521 can be identified at the outset and fixed with appropriate action, your truck is less likely to be damaged. 

However, if you temporarily resolve the error code, it could cause serious damage to your truck’s engine. It may even be that your truck’s engine is completely out of order. 

So take your truck to the nearest authorized mechanic shop as soon as possible and get it fixed.

How To Solve P0521 Error Code On Chevy Silverado?

If the Oil Becomes Dirty or Improper-

The most responsible reason behind the P0521 error code is not changing dirty engine oil and using improper oil. Change your truck’s engine oil at regular intervals. 

Generally, engine oil has to be changed every 3000 km. Also, always try to use engine oil approved by your truck manufacturing company.

If the Crankcase Is Dry-

The bottom of the cylinder bore is part of the cylinder block and the crankcase is made up of a stamped or cast metal oil pan that sets the bottom perimeter of the engine and also functions as an oil tank pool, or sump.

If the crankcase of your truck is dry or empty, immerse it using the appropriate oil.

Oil Pressure Is Low-

If your engine’s oil pressure warning light comes on or the oil pressure gauge signals, it means your engine has low oil pressure. It is because there is not enough oil. 

In this case, fill the engine cylinder properly with authorized oil. Make sure that the amount of oil is not too much or too little.

If There Is a Problem With the Oil Pressure Sensor-

Sometimes the oil pressure sensor encounters slight problems. In those cases, the advice of a skilled mechanic can be used to get rid of the P0521 code problem. 

However, if a serious error occurs, you may need to completely replace your truck’s oil pressure sensor. Then your costs will increase several times.

If There Is a Connection Problem With the Oil Pressure Sensor-

If your truck’s oil pressure sensor connections become loose or open, try re-plugging them in. On the other hand, if a connection is short, change it completely and add a new connection.

How Much Does It Cost To Solve The Error Code P0521 On Chevy Silverado?

It may cost you at least 150 to 250 dollars to fully identify and fix the P0521 code. However, the cost may vary depending on the location of the fixing and the depth of the problem in your truck.

Common Mistakes While Solving The P0521 Code

The most common mistake regarding the P0521 code is to completely replace the oil pressure sensor without inspecting it properly. However, the best solution is to replace the sensor completely if possible. In this case, the cost will be much higher.

A skilled mechanic will first monitor your truck problem closely and then take steps to fix it. And if he is not skilled, he will let you misunderstand without any observation.

Additional Comments To Consider Regarding The P0521 Code

If you own a vehicle, such as the Chevy Silverado, you should change the engine oil every 3,000 km. The most responsible reason behind the P0521 error code on your truck is not changing the engine oil regularly.


If you can understand the points mentioned in this article then it will not be difficult for you to observe the code P0521. Also if you can get a good idea about the engine oil level of your truck then no such error code will appear in your truck. 

So be careful and take care to keep your favourite truck away from such error codes and avoid the excessive cost.

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