How To Fix Error Code P0234 (Engine Overboost Condition)

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This article will educate you about error code P0234. This is an over-boost condition code. You will learn all about this error code and how to fix it. We will talk about what the definition and causes are as well. Let us dive in!

What Does Error Code P0234 Mean?

This error code will indicate that the powertrain control module or PCM has found that the boost pressure sensor is more than the specified input. This must be done for over five seconds to trigger the error code. This means that if the pressure is higher than the highest maximum level by 4 PSI for five seconds, you will have the error code P0234.

What Does Error Code P0234 Mean?

This code is known as a generic trouble code. This means that it is going to be available in vehicles that are newer than 1996. Keep in mind that each make and model of car will be slightly different.

Definition of Error Code P0234:

This means that the Powertrain Control Module has sensed that the boost was big. The pressure has exceeded the integrity of the engine. There will be a boost pressure sensor that will allow data to go back to the Powertrain Control Module. If this reading goes higher than the designated pressure, it will cause an error code to appear. This, in return, activates the Check Engine Light.

OBD-II Code P0234: Symptoms, Causes & Diagnose

Common Symptoms of Error Code P0234

The most common thing you will notice is the Check Engine Light will appear on your dash. At this point, you will not know the exact error code. However, here are a few things that could indicate it is error code P0234.

  1. You have no boost or turbo. You have a loss of power.
  2. The engine is overheating.
  3. The transmission is becoming hot or running harshly.
  4. The engine is knocking or making noises when accelerating.
  5. The engine is misfiring.

There are some instances where the engine will continue to run as it normally would. This is until there is a blow in a gasket or seal. The engine over boost will cause the seal and gasket to the intake and head to break.

Causes of Error Code P0234

There are a lot of reasons why this error code will appear. Plus, the symptoms are not always present. That is what makes this hard to diagnose sometimes. However, we have found some of the most common causes of this error code. They are as follows:

  1. The turbo/supercharger is damaged or sticking.
  2. The wastegate control solenoid valve is sticking.
  3. The hoses are clogged. This means that the boost pressure that has built up is not released as quickly as it should be.
  4. The connections/wires are corroded or faulty.
  5. Your wires are defective.

Diagnosing the Problem

  1. The first thing you need to do is grab a scanning tool. This tool will tell you what codes are present on your vehicle. If there is more than one code, ensure you are addressing all of them.
  2. Clear the codes if possible.
  3. Take the vehicle for a test drive to ensure it runs properly. If the light does not come back on, it could have been a fluke thing. However, if the check engine light comes on, you can get down to business.
  4. Make sure that your wastegate is not sticking or binding. You want to ensure that there are no kinks, damages, or any other obstructions in the relief hose.

If you do not have a scanning tool, local automotive stores will have some. These stores will read you the code that your vehicle reads. They will do this for free.

If you are looking for a more in-depth diagnosis, you can go to a dealership or mechanic. Your mechanic can perform a diagnostic test that local automotive stores cannot. Keep in mind a mechanic will charge you to do this diagnostic testing.

Fixing the trouble code P0234

Fixing the Problem

The most common problem when this error code occurs is your boost sensor. This is defective. In most cases, the pressure that this sensor is reading is incorrect. This, in return, causes the error to appear.

  1. You must replace a wastegate that is sticking.
  2. You should address the wastegate valve. If it is sticking or damaged, replace it.
  3. Look at lines. Ensure that they are not kinked or damaged.

The most common thing is that the wastegate sticks, and then you are going to get this code. However, if you have issues with overboost, your engine could fail. This is serious. This code is serious for vehicles that are not designed to have such power. It could cause a blown gasket or even an engine.

When you fix this code, you need to fix it based on your vehicle’s make and model. It will be different for each make and model.


If you are unsure how to fix the problem, ensure that you take it to a licensed mechanic. A professional will help you determine your problem and how to fix it. The mechanic will help you determine the best route to fix your vehicle.

You will find that the vehicle goes into what is known as a limp mode. Anyone who knows vehicles knows this is when the vehicle does not have acceleration. This is a tell-tale sign that it is an error code P0234.

Wrapping Up

This is something that can be difficult if you do not have prior knowledge. If you do not have mechanical experience, it may be wise to bring your vehicle to a professional. However, if you are mechanically inclined, this job may be simple for you. You are taking the time to properly diagnose the problem is key.

You do not want to spend money fixing items that are not needed. You want to focus on what items you need to fix. Spend your money here.