P0332 OBD-II Code: Symptoms + Fixes [Knock Sensor]

P0332 OBD-II Code

As you probably know, your car is a network of electrical systems whose main purpose is to keep your vehicle in good shape so you can drive it on the road.

These electrical systems are monitored by sensors and these sensors send live data to your engine control module (ECM). The ECM monitors all of this data and when something gets wrong it makes sure to notify you with a warning light on the dashboard.

Let’s say that you have a P0332 Code which is related to your Knock Sensor circuit, the ECM detects this issue and illuminates the Check Engine Light (CEL).

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So, if you are experiencing issues with this code, make sure to stay with me through the end of this article to learn what it means and how to fix it.

Let’s dive in!

What Code P0332 Means?

If you are using an OBD II scanner this code will appear under the name “Knock Sensor 2 Circuit Low Input (Bank 2)“, so let’s first explain what the Knock Sensor does.

The primary purpose of the knock sensor is to manage and monitor the detonation(ping) in your engine. It’s a form of combustion which can cause severe damage to your car, especially if you leave it unchecked.

So, if the ECM receives a low signal from this sensor this means that it won’t be able to properly handle the problem. In other words, if the detonation in your engine is not monitored perfectly this can lead to an absolute engine failure and therefore a costly repair by your side.

Of course, this is the worst-case scenario, but a bad knock sensor could also lead to higher emissions and failure on the emission test, and other engine problems.

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What is the severity of this issue?

This issue can be explained as 4 levels of severity:

  1. Low – The P0332 code appeared, but you didn’t notice any changes in your vehicle’s performance.
  2. Moderate – The trouble code continues to appear after you cleaned it with an OBD II scanner and you may experience slight engine knocking and bad fuel efficiency.
  3. High – Significant engine knocking, loss of power, performance issues, bad fuel economy.
  4. Severe – Here you can experience severe power loss and even fail to start your vehicle. In most cases, this indicates serious engine damage and your car should be inspected by a professional mechanic.

Possible Causes Of Code P0332

There are a lot of possible causes of the code P0332, but let’s mention the most common ones.

  • Faulty Knock Sensor – The sensor itself may be bad and you need to replace it.
  • Problem with the wiring – Any of the connectors or the wires may have gone bad.
  • Cooling problem – If you have a problem with the cooling system this may cause your engine to overheat.
  • EGR System – If the EGR is faulty, most of the time you will get a code P0401 along with the code P0332.
  • Air/Fuel Ratio – This can be due to a bad MAF sensor, which also triggers the knock sensor problem.
  • Rarely A Faulty ECM – It’s not a common problem, but it’s certainly possible.
  • Bad Injector – A bad injector can cause engine knocking and you can experience low fuel pressure.

Here you can see that the problems are oftentimes related to one another, that’s why it is important to diagnose them correctly.

What Are The Symptoms Of the P0332 Code?

a mechanic making the obd 2 scanning

As I mentioned above, this diagnostic trouble code (DTC) has 4 levels of severity. Depending on your situation you may not experience any major difference in your engine’s performance other than just a Check Engine Light (CEL).

But you may also experience some more serious problems, like the ones below.

1. Power Loss

If the reading from the knock sensor is not correct, this may cause your spark plugs to ignite the air/fuel mixture late and therefore your engine loses power.

Now let’s put it simply, a delay in combustion is stopping the engine from fully burning the air/fuel mixture. This is a serious problem and can not only cause power loss but also severe engine problems.

2. Bad Fuel Efficiency

This is related to the symptom above. 

If the fuel system is too rich, the engine cannot burn it properly and therefore you can experience a higher MPG. On the other hand, if the fuel system is too lean, that means that the engine does not have enough fuel to burn and you get a decreased MPG. 

Usually, you can soon realize that there is a problem if you notice sudden spikes in your overall MPG.

3. High operating temperature

As we said above if the knock sensor is malfunctioning this can cause incorrect ignition timing. This is undoubtedly one of the reasons that may cause your engine to overheat because it is not operating at its normal values.

Of course, this can also be caused by a bad temperature sensor or any other problem with the cooling system, and it’s best to get it checked immediately to resolve the issue.

4. Increased Emissions

It’s a well-known fact that a bad knock sensor can seriously damage your catalytic converter. And as you probably know, the catalytic converter is what decreases your emissions, simply said.

So if this catalytic converter is damaged, your engine can’t convert toxic particles into less harmful emissions. 

5. Engine Pinging/Knocking

If the OBD-II error code P0332 appears and the knock sensor sends a low input signal to the ECM, you may hear a knocking sound coming from your engine.

And if the ECM can’t correct the early ignition timing because of the knock sensor and its circuit, this will result in engine pinging or knocking, leading to bigger problems if not resolved quickly.

How Much Does It Cost To Fix?

OBD2 scanner is connected for the fuel pressure reading

To be completely honest with you, there’s not a one-fix solution to this problem and the price can vary a lot to fix this OBD-II trouble code.

As I mentioned above, the reasons for this code can be from a faulty knock sensor to damaged wiring and an overheated engine. Most of the time this problem can be fixed by replacing the knock sensor and the price can vary between 120$ – 200$.

However, if there’s a bigger problem like damaged wiring or an overheated engine the price can jump to literally thousands of dollars.

The only way to know if there’s a bigger problem with your vehicle is to use a professional bidirectional scanner and if you currently don’t have one, it is best to leave your vehicle at the closest shop and let them diagnose the problem.

Typically these shops charge between 80$ – 150$ an hour which is the estimated time in which they found the issue. After that, they can give you an estimated price for the repair of your P0332 knock sensor problem.

In conclusion, the starting price for fixing this problem is around 200$ and it can reach thousands. That’s why it is super important to get it fixed as soon as possible to avoid any bigger damage to your vehicle.

Potential Solution For DIY Enthusiasts

If you are a DIY enthusiast and don’t want to spend a lot of money in expensive shops and change unnecessary parts I will list some steps that can help you to fix the trouble code P0332. 

Keep in mind that this is not a beginner-friendly problem and it requires quite a bit of knowledge to be diagnosed properly, however, this doesn’t mean that you can’t try to fix it yourself.

Just make sure to follow the steps below to diagnose and fix this problem.

Step 1: Scan and Clear The Codes First

At this point, it’s more than obvious that you will need an OBD-II scanner to scan and clear the codes. Make sure that the P0332 code is still current. You can clear the codes and go for a short 15-20 minute test drive after that scan it again, and if you see the knock sensor code again that means that the issue is still there.

Step 2: Check The Wiring

If you are sure that the code is present it’s time to check the wiring harness. Find the location of the knock sensor and start inspecting the wires visually. Follow the harness all the way to the PCM and make sure that there isn’t any damaged or corroded wire. 

If everything looks good, move to the next step.

Step 3: Check The Signal

You can do two things here. Use a multimeter or use a bidirectional scanner to check the voltage that comes from your PCM to the knock sensor circuit. 

If you don’t have a scanner, you will have to disconnect the knock sensor connector from the sensor and plug the multimeter in there. With a normally operating harness, you should get around 5 volts which means that the harness is good.

Of course, the easier way to do that is with an OBD scanner. Go into the live data of the sensor and make sure the voltage there is correct.

Step 4: Replace Harness Or Sensor

If you made sure that the harness is okay by checking the voltage, it’s time to replace the sensor. However, if you found an issue with the harness it’s best to replace it by placing a new wiring cable from the connector to the PCM.

Bonus Step: Check Temperature Sensor

If your temperature sensor is faulty, this can certainly cause an engine knock and the knock sensor’s code. If the harness or the temperature sensor itself goes bad this will send false information to your PCM and this will trigger your CEL plus the P0332 code.

Related Article – Decoding the Wrench Light: What It Means for Your Car

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