P0021 Code – Meaning, Causes, Symptoms (& How To Fix)

With so many moving parts in the engine, it’s no wonder problems arise over time. You need to be able to identify what next when the Check Engine Light turns on.

We will be discussing the P0021 problem code and its causes in this guide. This guide will show you how to treat the potential symptoms and offer some suggestions. 

Definition of code P0021

• P0021 – Camshaft Position A – Timing Over-Advanced or System Performance (Bank 2)
• Nissan: Camshaft Variable Timing Control – Bank 2 – Performance

What is the P0021 Codification?

P0021 can be considered a general trouble code. It indicates that the Engine Control Module's (ECM), determines that the bank 2 intake camshaft is more complex than the parameter allows. This advanced state means that the timing of camshafts has changed beyond what it should.

This applies to all major automakers except Nissan. If you spot the code in a Nissan model, the meaning is Camshaft Variable Timing Control – Bank 2 – Performance instead, although the cause could still be the same. 

P0021 Trouble Code Symptoms

Check Engine Light is the most common sign of the code P0021. However, it’s also quite likely that there are performance issues occurring as a result of the fault.

These are some of the possible symptoms.

Your symptoms will depend on the position of your camshaft timing relative to its normal location. 

The P0021 code: Causes

P0021 can be caused by many different things. It is important that you do a thorough diagnosis to determine the cause. These are only a few possible causes.

Is the P0021 Code Really Serious?

Very severe – You may not notice any severe issues at first when the code appears. It is possible to cause severe engine damage if your timing chain or belt breaks.

You could be in an accident if your engine stops. You are wasting fuel and contributing to excess emissions. 

How can you fix the P0021 code?

There are many ways to get back on your feet, depending on what you discover during diagnosis. These are some of the possible solutions you may find.

• Make sure to change your filter and oil.
• Replacing the camshaft oil control valle
• Fix wiring or harness issues
• Replace timing valve control solenoid
• Replace or fix timing chain, belt, or tensioner
• Replace camshaft position sensor

Common errors in P0021 diagnosis

There are many components to be checked, so mechanics may not bother checking the oil. All problems could result from low or contaminated oils.

A filter and oil change would be cheaper and more efficient. That’s why you should always check that first when encountering the P0021 code. 

How to diagnose P0021 Trouble code

Even if you aren’t a professional mechanic, you can troubleshoot the P0021 code the same way that they would. With some simple tools and expertise, it’s easy to figure out what’s wrong if you follow the right steps.

Below are some suggestions.

1. Check all trouble codes. You can remove any trouble codes that are not needed immediately and then restart the engine. It is useful to freeze frame data in order to pinpoint problems.
2. Check the oil condition. If it’s low, you can fill up the reservoir to appropriate specifications. An oil change is the best option if the oil has become contaminated. Don’t forget to put a new filter in too, ensuring that no sludge is left behind. 
3. Take out the camshaft oil valve from bank 2, and connect power with fused jumper wires to the solenoid. A ground connection must also be provided. Don’t do this for more than a couple of seconds. If it’s working right, it will click or move. If it's not working right, the device should be fixed. To avoid any damage, use a proper repair manual.
4. Verify camshaft timing. If it is incorrect, an diagnostic procedure to the timing belt/chain must be performed.
5. You should inspect the harness and electrical wiring. If there’s any sign of damage, you need to repair it.

Beyond these steps, you could reference your vehicle’s service manual to see if there is any more help based on your model type. Otherwise, it’s best to talk to a professional mechanic for further guidance. 

Repair costs estimated at P0021

When your diagnosis is done, you'll know what repair work needs to take place. The next step is to find out the estimated cost. These are some common repairs and estimated repair costs, if the labor and parts are included. It might cost less if you perform the job yourself.

• Engine oil and filter change – $45-$150
• New camshaft oil control valve – $125-$350
• Repair harness 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

The P0021 code is a good starting point for mechanics.

Sadly, there’s always the possibility that the engine oil is full of sludge and there could be permanent issues. Because the oil control valves and camshaft passages are smaller, thick oil can’t get through easily.

If you change the oil but are still noticing trouble with the engine performance, it’s possible permanent damage has occurred. To have your car examined more closely, take it to the mechanic.