Knock Sensor Code -Trouble Code Meaning, Causes-Symptoms, Fixes

The knock sensor is a naïve-looking component of your vehicle’s engine. But the importance of this naïve-looking component is very much if you consider its functions. You can say the knock sensor is the ear of the engine. It hears the vibrations coming from the engine and after making them into signals, sends them to the control unit.

how to fix knock sensor code

Thus knock sensor helps the engine to eliminate any possible threats. For this reason, you would always want a properly functioning knock sensor.

A knock sensor helps engines to monitor the powertrain control module (PCM) by “knocking.”

In this article, we are going to discuss various knock sensor codes, why they keep coming back, and possible measures to get rid of the problem.

Why Knock Sensor Code Keeps Coming Back?

Let’s answer another question before this one. When do you get to see a knock sensor code? A knock sensor code may appear due to any problems regarding the engine knocking. A code may even appear if the knock sensor becomes bad itself.

For different incidents, you will see knock sensor codes. And by evaluating the codes, you will know what happened to the engine. But sometimes even after the measurement to tackle the knock sensor code issue, you may still see the knock sensor codes keep coming back. It can happen because of the following-

  • Damages in wiring
  • Short circuit in wiring
  • Wrong mounting
  • Mechanical damage
  • Corrosion
  • Faulty knock sensor

If you take the symptoms regarding knock sensor issues seriously, you will know the reason for a faulty knock sensor and also the reason for the knock sensor code. A faulty knock sensor is the main culprit for the frequent knock sensor codes even after the fixation of a particular code.

You have to change the knock sensor as soon as you identify there is a problem with the knock sensor. And make sure to change the knock sensor after every 150,000 miles to keep everything healthy.

Knock Sensor Code p0332


You will see a p0332 code whenever the knock sensor gives a very low reading to the powertrain control module (PCM). In this situation, the PCM won’t be able to address the possible issues. That is why this code is serious and you need to get rid of this code as soon as possible to get the knock sensor into a properly working condition.


The symptoms of a p0332 code are-

  • During acceleration, you will face engine pinging
  • Power loss
  • Too much heat in the engine, even when the engine is operating normal tasks.

Possible reasons

The common reasons behind the p0332 code are-

  • Too lean fuel/air ratio
  • Faulty knock sensor
  • Problematic EGR (Exhaust gas recirculation)
  • Issues in the cooling system

How to fix the p0332 knock sensor code

You can address the p0332 code by following the steps mentioned below-

1. Change the knock sensor

2. Fix the main issue of the EGR

3. Make sure that the circuit and sensor are grounded appropriately.

4. Change the broken wires of the sensor circuit

5. In some rare cases, you may even need to replace the PCM to get rid of the code.

How To Diagnose GM Knock Sensors – P0327 & P0332

Knock Sensor Code Bank 2

You can divide the knock sensor into two banks. Bank 1 and Bank 2. Bank 2 is actually the container of the second cylinder. That is why you can tell the side containing the second cylinder is bank 2. Usually, the knock sensor code p0332 indicates the issues regarding bank 2. However, bank 2 may become faulty if you see the p0325-p0334 codes.

Knock Sensor Code p0327


The job of the knock sensor is to send signals frequently to the PCM about any type of sound. After that, the PCM will take the necessary measures to tackle any possible issues. If the knock sensor is unable to send signals to the PCM, especially if there is an issue in bank 1 (or single sensor), you will see the p0327 code.


You will know the appearance of the knock sensor code p0327 by various symptoms. Let’s have a look at them-

  • Problems in the acceleration
  • Spark knocking
  • Power loss
  • Check engine light (turned on)

Reasons behind the Error Code P0327

  • Issues with the knock sensor
  • Damaged wires in the sensor circuit
  • Problems in the cooling system
  • Defective EGR
  • Wrong fuel/ air ratio

How to fix the p0327 knock sensor code

You can fix the p0327 code by taking the following measures-

1. Fix the engine cooling system

2. Repair or replace the ECU (Engine Control Unit)

3. Remove the faulty knock sensor

4. Do any repair in the EGR system if necessary

Knock Sensor Code p0328


The error code P0328 simply tells us that there is an issue with the circuit of knock sensor 1. You will see the error code when there is too much high voltage going on in the circuit. The knock sensor will transfer the signal to the PCM or ECU. And then, the PCM will force the check engine light to illuminate. In this process, you will know that something has gone wrong.


The common symptoms that often lead us to the knock sensor code p0328 are-

  • You will notice a noise like pinging in the engine on the higher speeds
  • There will be a loss in power of the engine
  • You may see some hesitation in the engine, you will feel it
  • Check engine light, this is the most reliable symptom that will lead to a possible knock sensor code issue

Reasons behind the p0328 code

The p0328 code may pop up due to the following reasons-

  • Defective ECU
  • Overheating engine
  • If the fuel pressure is low
  • Defective knock sensor (bank 1)
  • Too lean air/ fuel ratio

How to fix the knock sensor code p0328

You can get rid of the p0328 code by taking the following steps-

  1. Replace the knock sensor
  2. Change the ECU
  3. Get rid of the overheating issue
  4. Use the right engine oil for the engine

Knock Sensor Code p0330


You will face the error code p0330 only when there is a malfunction in the circuit of the knock sensor 2. The p0330 code has a relation with the codes like p0325, p0326, p0327, etc. The ECU will force the check engine light to get illuminated if there is a malfunction in the circuit. And the light will be there unless you clear the code or repair the vehicle.


You will see the following symptoms if the issue is about the code p0330-

  • You will feel something is not right with the engine as the engine will show some hesitation
  • You will face a power loss of the engine
  • Sometimes, there won’t be any symptoms at all except the check engine light

Reasons behind the p0330 code

The most common reasons behind the p0330 code are-

  • Defected ECU
  • Problematic knock sensor 2
  • Too lean air/ fuel ratio
  • Fault in the engine cooling system
  • Problems in the wiring

How to fix the knock sensor code p0330

You can take the steps mentioned below to tackle the code-

  1. Replace the faulty ECU
  2. Address the fuel issue
  3. Fix the engine cooling system
  4. Change the knock sensor

Knock Sensor Code p0326


The simple meaning of the code p0326 is that there is a performance issue in the circuit of knock sensor 1 (single sensor or Bank 1). If the voltage becomes too high and way beyond the acceptance level prescribed by the manufacturer, you may see the code p0326. As something like spark knock is a really serious issue, you should not try and overlook this knock sensor code.


You may find about the knock sensor code p0326 with the following symptoms-

  • Loud knocking from the engine
  • You will hear a pinging sound when you try to accelerate
  • Loss of power of the engine
  • Hesitation of the engine

Common reasons of code p0326

The most common reasons behind the p0326 knock sensor code are-

  • Defected knock sensor
  • Faulty wiring in the knock sensor circuit
  • If the connector gets unplugged
  • Defected PCM (it is very rare)

How to fix the p0326 knock sensor code

1. Try to resolve the issue with the wiring of the knock sensor

2. Change the knock sensor if it gets too bad

3. Change the PCM

4. Plug the knock sensor again

Knock Sensor Quick-Fix

The knock sensor is a piezo electric or crystal component. The knock sensor detects faulty engine knock and sends a voltage signal to ECM to fine-tune ignition timing. It is act like a microphone and screwed to the engine block or manifold. Interestingly, it tunes between 6 to 9 thousand Hertz.


What happens when a knock sensor goes bad?

There will be several outcomes. The first and most common problem you will face is engine knocking. Maybe you have an idea how bad this knocking problem is. You may not be able to accelerate the engine properly. And the low fuel mileage is another possible outcome of a bad knock sensor.

What causes a knock sensor code?

There are various reasons behind a knock sensor code. You may get a knock sensor code if the knock sensor goes bad itself. Anyway, if the knock sensor can’t provide signals to the PCM about the vibrations of the engine, you will see a knock sensor code.

How much does it cost to replace a knock sensor?

It is quite hard to tell. You have to save around $550 to $650 to get everything done regarding the replacement. Around $340 for the new knock sensor and $200 for labor cost. However, the cost may differ as per your location and the vehicle model.

Can I drive with a bad knock sensor?

In fact, yes. But this “yes” depends on your level of emergency. Except for a high-level emergency, you should replace the bad knock sensor as soon as you assure the knock sensor problem. The longer you drive with the bad knock sensor, the more you will damage your vehicle.


A bad knock sensor is never an ideal component for your vehicle. You might want to replace this one as soon as possible. Because you will not do anything but damaging your vehicle if you continue driving with a bad knock sensor.

We have tried our best to get you acquainted with some of the common knock sensor codes. And we hope you will be a better driver by acknowledging the knock sensor problem better and fixing the issues ASAP. Don’t forget to share your thoughts about the article and leave a comment if you have any queries.

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