P0021 – What You’ll Need To Fix This Error Code

P0021 – What You’ll Need To Fix This Error Code

The error code P0021 is one of the most common and generic powertrain codes that are present out there. This error code being generic means that it is the same for several makes and models of vehicles, even from different manufacturers. Alongside that, this code is common which means that there are several ways to get rid of this problem. This error code typically involves your vehicle’s variable valve timing system.

In this article, we will educate about the causes, symptoms, and fixes of the error code P0021. You will also learn about the variable timing valve system and what other things that can trigger this code. A simple example of another thing that can cause this problem is the camshaft timing system. So here is a breakdown of everything you need to know about the error code P0021.

P0021 Code

The detailed description of the error code P0021 is more complicated than what meets the eye. This OBD-2 code means that the camshaft has moved or advanced beyond the predetermined position. This motion is usually considered to be disrupted when the camshaft happens to be advancing or retarding. Once the camshaft position sensor, near the bank-2 intake, picks this up it sends information to the electronic control module.


The ECM once it receives the signal from the crankshaft, camshaft, engine, and temperature controls, it further sends information to the intake valve timing control valve. This message is based on several things like the speed and temperature of the engine. Once that is completed, the timing of the intake valve changes to direct oil flow which controls the angle of the valve, either advancing or retarding it.

A long flow is responsible for the advances of the valve, whereas a short flow is responsible for retarding it. When the flows are equal, the oil pressure is stopped so the angle can be recalibrated. This is when the engine decides to show the check engine light and the error code P0021.

Variable Valve Timing

To put it in layman’s terms, the engine for the modern car has evolved through the years. One of the main advances made is the incorporation of the variable valve timing system in the engine. This system allows your vehicle to be much more powerful and efficient under different driving types and conditions.

As said before, the PCM uses the data from the camshaft sensors and crankshaft position sensor to determine their respective positions. Using this information, the PCM commands the VVT to apply oil pressure to an actuator on the end of the camshaft. As a result, the actuator changes the position of the camshaft, with further alters the engine’s valve timing.

Intake Camshaft Position Timing Over Advanced Bank 2

There are a number of things that might cause your car to give the error code P0021. This makes it extremely important to make a complete diagnostics before you jump to any conclusions. Hence here are just some of the causes that might be triggering the error code P0021.

Low engine oil – For this whole process to take place easily, there needs to be the proper amount of oil present. A lack of oil can cause friction which can further cause the camshaft and crankshaft to not move efficiently. This further might trigger the error code P0021.


Failing camshaft control valve – A failing camshaft control valve might be the reason for the lit-up check engine light. A camshaft control valve is there to operate and control the flow of air, fuel, and exhaust gases. Any problem with any of these will cause your problem to not work at its optimum condition.

Electrical connections are damaged or shorted – A problem with the electrical connections in a car will cause several things to go wrong under the hood. One of these problems includes the error code P0021. If the electrical connection has gone bad or is even weak, it will not allow the components like the valve system or the sensors to work properly. Hence you will get the error code P0021.

Here are just some of the causes that might lead your car to face the error code P0021. There are some other problems that might cause this problem, they are-

  • Stuck or defective timing valve control solenoid
  • An issue with the PCM, such as software in need of an update
  • Worn or damaged timing chain
  • A failed timing chain tensioner or guide

P0021 Error Code Symptoms

It can be extremely stressful and scary when your car starts to malfunction or the check engine light turns on. That is why to diagnose this problem you need to hook up your car to an OBD reader to know what problem your car is facing. But everyone does not have an OBD-2 scanner lying around so here are some symptoms for the error code P0021.

1. Check Engine Light

A check engine light on the car is to inform you if there is any problem with the engine. This symptom is common with several other error codes too. A check engine light only notifies the owner of a problem with the engine but does not tell what problem is it.


You can use an OBD-2 scanner to know more. Hence, if you don’t have one and you see a check engine light on your dash the first thing to do is to take your car to a mechanic to get it checked out. To find out more, check out our guide on the check engine light after oil change.

2. Rough Running Engine

As said before, an error code P0021 can be extremely difficult on your engine and your car in general. Hence one of the symptoms that come with this code is the rough riding of the engine. This error code means that there is some problem with the variable valve timing system. It is responsible for controlling the air and fuel that enters the combustion chamber.

When there is a difference in the fuel and air that needs to enter the combustion chamber for efficient working does not get delivered, the engine starts to run extremely rough. A rough running engine means that the car misfires or there is a sudden drop or increase in its power output. This can be extremely dangerous if neglected.

3. Decreased Fuel Economy

Another one of the symptoms your car can face is the fact that your car’s fuel economy will be affected majorly. The error code P0021 means that the camshaft position has changed and this happens usually due to a problem with the variable valve timing system or the camshaft timing system. Both of them are responsible for making sure that the engine works in the most efficient way possible.

If there is a problem with any one of these systems the car can start to lose this efficiency that manufacturers spend time and money perfecting. There can be more fuel than required being put into the combustion chamber.

This will not only make the car work extremely rough but also will have a huge impact on the fuel economy. More fuel being used means fewer miles per gallon with compromised performance.

3. Failed Emissions Test

Another symptom on the list of the error code P0021 is the fact that your car will fail an emissions test while dealing with this problem. This happens due to the fact that there are problems with the air-fuel ratio, the variable valve system as well as the camshaft timing system. So if the engine starts to malfunction, the engine does not run at its optimum conditions.


There is more air or more fuel in the combustion chamber than it needs to be. That is the reason why the car will not be up to the state’s regulations when it comes to the emissions they produce.

How To Fix The Error Code P0021

Luckily, getting rid of the error code P0021 is relatively easy in comparison to the scary symptoms that it has. Most of the people usually leave repair jobs that might seem difficult to their mechanic. This is usually because they lack the skills, knowledge, and expertise that are required for this job. However, that does not mean that you cannot fix this particular error code P0021.

All you need to know is that you need to have the necessary equipment on hand and some adequate DIY automotive skills.

Tools That You Need

In order to fix this OBD error code, you would need some stuff that is available to almost anyone who is curious about looking under the hood. If you are planning to get rid of this error code DIY style, here are the things that you would need.


The first thing you need to do is to get an OBD-2 scanner and a multimeter with that. Alongside these, you would need a basic set of tools like a screwdriver, wrench, etc. Once you have these things with you, you would need to get a hold of the car’s manual. Last but not the least, you need cleaning rags, which is important with all DIY projects.

How To Fix This Error Code

The first thing that you need to do is to hook up the OBD-2 scanner to your car and double-check for the error codes before you clear them. The next thing you got to do is use a multimeter to check if the car’s solenoid has not failed. Check the multimeter for an OHM reading which should be between 7-12 which is the ideal range. If not then it might need to be changed.

The third thing you need to do is run a pin test between the solenoid and the ECM. Before you start to make any repairs, you need to check the wires or connect to most of the sensors. You also need to check for sludgy oil and ensure that the correct viscosity is used.

The next thing you need to do is to run the OBD scanner again. This will help you to collect the freeze-frame data to learn all the codes and data that were triggered by the ECU. Once you have collected all this data, reset the ECU and clear the error code. Retest the vehicle to see if the code still exists.

Use the handy tools mentioned earlier to tighten the harness terminals at the solenoid and clean the terminals. Lubricating the contacts with a type of oil ideal for electric contact is important. Changing the engine oil and filter is the next thing on the list. Repair any wiring and replace any sensor that looks like they are malfunctioning. If you are not able to figure things out, you need to show your car to the mechanic.

Common Mistakes Made When Fixing Error Code P0021

This error code P0021 can cause you a lot of trouble if not diagnosed properly. This choice can be mistaken for several things. Here is a list of guidelines that need to be looked out for while diagnostics.

  • You need to visually inspect the electrical connections for damages.
  • Inspect the engine oil’s viscosity and ensure if it is the correct one.
  • Reset and retest the OBD-2 scanner.
  • Go through the owner’s manual to pinpoint the test exactly without skipping any steps.

Here is everything you need to pay special attention to.

Price Of Fixing The Error Code P0021

Once you are done with your diagnostics, you know what all is needed to be replaced or repaired. Hence the next question on everybody’s mind is the fact that how much will everything cost to get your car back up and running.

Here are some of the common fixes and their repair cost, so that you have a better idea of what to expect. These repair costs usually include parts as well as labor, so if you do it as a DIY project it is much cheaper.

  • Engine oil and filter change – $45-$150
  • New camshaft oil control valve – $125-$350
  • Repair connectors or wiring issues – $50-$550
  • Replace timing valve control solenoid – $150-$450
  • Repair camshaft belt or chain – $1000 – $5000
  • Replace camshaft position sensor – $50 – $200

P0021 Nissan

Nissan has dominated the automotive market for a very long time. They are appreciated for their comfortable and affordable sedans, their SUVs and pickup trucks, and their sports cars. One of the most common problems faced by all of these Nissan cars is the error code P0021. This error code means that there is a problem with the position of the camshaft which is causing your engine to run rough.


The mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake valve. The ECM is responsible for controlling most of the things involved in this process. Things like the camshaft position, crankshaft, engine speed, the engine coolant temp, etc. the ECM furthermore sends on and off signals to the intake valve timing control valve depending upon the driving conditions.

Any problem at any given time with any of these parts can cause the vehicle several problems. These problems usually include things like a rough idle, rough running of the car, bad fuel economy, and a check engine light. These are the symptoms that might show that your Nissan is facing the error code P0021.

P0021 Subaru

Subaru is one of the top manufacturers out there in the automotive industry. They are known for their 4×4 drivetrain and most of their affordable sports sedans and wagons. Subaru cars are not a stranger to the error code P0021. As said before this error code usually specifies that there is an issue with the camshaft position. When your car is facing the trouble code P0021, it means that the intake camshaft in bank 2 is more advanced than the ECM has it to be.


This error code is usually caused due to a few reasons that if paid attention to and properly maintained can be avoided. Here is a list of all the causes that might cause your car to face the problem P0021.

Here is the list of the causes for the error code P0021 on a Subaru.

  • The engine oil has become extremely dirty.
  • There is a dip in the engine oil or the levels of the oil are extremely low.
  • The engine oil used is of the wrong velocity.
  • The camshaft variable valve timing control solenoid has failed or is malfunctioning.
  • The camshaft phaser is seized in the advanced position.
  • Continuous oil flow to Variable Camshaft Timing chamber.

P0021 Infiniti

Infiniti is a car manufacturer that has several cars that have done amazing in the automotive market. And like some of the manufacturers taken about before, the Infiniti is not some manufacturer that has not faced the error code P0021. From the Infiniti lineup, the G35 is one car that has faced this error code a number of times.

Here are some of the symptoms you might see on your Infiniti G35 that might notify you about the error code P0021.

Here is a list of symptoms you need to look out for.

  • The check engine light turns on.
  • The engine has a hard or a rough start.
  • Your car might have a rough running engine.
  • The car might start to stalling while driving.
  • There might be a rattling or knocking noise coming from the engine.
  • There will be a major drop in the fuel economy.
  • Your car will fail the emissions test.


The error code P0021 can be extremely problematic for the vehicle and it should not be ignored. We have mentioned everything you need to know to diagnose and fix this problem. To avoid triggering this error code in the future, you need to check your engine oil according to the manufacturer’s standards. Alongside that only use, the oil viscosity is recommended in the owner’s manual. You also need to keep checking the wiring as it is extremely important.

Frequently Asked Questions

Here is a list of all the common questions that people have regarding the error code P0021.

How Do I Fix Code P0021

As mentioned, there are certain steps that need to follow to help you get rid of the error code P0021. Alongside that, the information about the tools needed for the jobs is also been mentioned previously in this article. When we talk about getting rid of the problem the things you need to do is double-check the problem with the help of an OBD-2 scanner. You need to inspect the data from the scanner to know more about the problem. Secondly, you need to closely inspect all the connections and wires to make sure that there is no electrical issue. After that, you need to check for oil sludge or any loss of oil that might have triggered this issue. You also need to make sure that the oil has the correct veracity and that there is no leak in the oil system. The next thing you need to do is clear all the codes from the OBD scanner and restart your car to see if the error code still shows. If it does you need to check the owner’s manual to pinpoint tests for the P0021 code.

How To Test VVT Solenoid With Multimeter

It is extremely important to check the variable valve timing solenoid which diagnoses the error code P0021. You can test this with the help of a digital multimeter. So to start this process you initially need to make sure that you have unplugged the electrical connection powering the solenoid. Secondly, you need to turn the key to the on position or the ignition position. Make sure that you do not start your engine. After completing that you need to grab the digital multimeter and set it to DC (volt). Touch the two leads of the multimeter to the electrical connections. Do you see any voltage? If not it means that you need to check the wiring in your car for any shorts. The voltage needs to be between 8 and 12 DC to show that everything is working completely fine.

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