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P0602 code — how to fix error fast

The P0602 code plays a pivotal role in a vehicle's prime condition.

A person is holding a tachometer in a car.
A man in a blue jacket smiling in front of a red wall.
Filip Gromovic July 7, 2023 |

As a driver, one of the worst OBD2 codes you can experience with your car is the P0602 code. It’s often even lethal for the engine’s performance, which is why most drivers regret the mistake of not acting on time to repair the issue.

Luckily, we’ll guide you through the P0602 code meaning and fixing the code so you can easily overcome this issue. We’ll also be recommending you some methods of prevention once it’s all done with solving the code, which is why you should stand by for detailed instructions.

Why you can trust REREV’s OBD2 code advice: Our automotive expert researchers with experienced mechanics undertakes a thorough research methodology to deliver precise insights on OBD codes. Find out more about OBD2 codes research process..

What does the P0602 code mean?

The P0602 code is a diagnostic trouble code that indicates a malfunction in the control module of a vehicle. This code can appear in any type of vehicle, whether it’s a car, truck, or SUV. Understanding this code is crucial for diagnosing and fixing the underlying issue before it becomes more severe.

Moreover, if the control module fails, it can lead to some serious problems with the engine. The module uses information from various sensors to manage the fuel injection and combustion processes and that’s why it’s so important to act on time upon the first signs of this code.

What causes the P0602 code?

The P0602 code can be caused by a variety of issues, including a malfunctioning control module, a damaged wiring harness, or a faulty battery. Here are some of the potential causes of the P0602 code:

Malfunctioning control module

The control module is responsible for managing various systems in your vehicle, including the engine, transmission, and brakes. If the control module malfunctions, it can trigger the P0602 code. This can be caused by a variety of factors, including electrical issues, software glitches, or physical damage to the module.

Damaged wiring harness

The wiring harness in your vehicle is responsible for transmitting electrical signals between various components. If the wiring harness is damaged or corroded, it can cause electrical interference that triggers the P0602 code. This can be caused by exposure to moisture, corrosion, or physical damage.

Faulty battery

A faulty battery can also cause the P0602 code to appear. If the battery is not supplying enough voltage to the control module, it can trigger the code. This can be caused by a variety of factors, including a dead battery, a faulty alternator, or a damaged battery cable.

Which car models does the P0602 code affect the most?

While almost any car out there can face code P0602 due to a faulty ECM, there are some vehicles that are more prone to this code than others. This is most likely due to the design of the module and its shorter lifespan compared to other vehicles. So, we decided to do some more digging to deliver the list of commonly affected cars to you:

  • Ford Focus: The 2001-2005 Honda Civic is one of the most commonly affected car models when it comes to the P0602 error code. This issue is often caused by a faulty ECM in these vehicles.
  • Dodge Grand Caravan: The 2001-2007 Dodge Grand Caravan is also known to experience issues with the ECM, leading to the P0602 error code.
  • GMC Savana: The 2003-2007 GMC Savana vans have been reported to have problems with their ECMs that can trigger the P0602 error code.

How to diagnose the P0602 code?

Diagnosing the root cause of this issue can be challenging and may require specialized tools and expertise. Here are some of the main ways that mechanics diagnose the code P0602:

Using an OBD2 scanner tool

The first step in diagnosing the P0602 error code is to use a scan tool to retrieve the trouble codes stored in the ECM’s memory. This will provide information on what caused the ECM to trigger the error code.

Performing a visual inspection

A visual inspection of the ECM and its wiring can help identify any visible damage or issues that might be causing the problem. This can include checking for corrosion, loose connections, or damaged wires.

Testing the ECM

In some cases, it may be necessary to test the ECM itself to determine if it is functioning properly. This can involve using specialized equipment to check the ECM’s internal circuits and compare them to factory specifications.

Battery and charging system check

The P0602 error code can sometimes be triggered by low battery voltage or a malfunctioning charging system. A mechanic may perform a battery and charging system check to rule out these possibilities.

How to fix the P0602 code

Fixing the P0602 code depends on the underlying cause. Here are some of the potential fixes for each cause of the code:

Malfunctioning control module

If the control module is malfunctioning, it will need to be replaced. This can be a costly repair, as control modules can be expensive and require specialized programming.

Damaged wiring harness

If the wiring harness is damaged, it will need to be repaired or replaced. This can be a labor-intensive repair, as the harness may need to be removed and rewired.

Faulty battery

If the battery is faulty, it will need to be replaced. This is a relatively simple repair that can be done quickly and easily.

How to prevent the P0602 code

Preventing the P0602 code requires proper maintenance of your vehicle’s electrical systems. Here are some preventative measures you can take:

  1. Regularly inspect the wiring harness and connectors for damage or corrosion.
  2. Replace the battery as needed, and make sure the alternator is functioning properly.
  3. Perform routine maintenance on your vehicle’s electrical systems, such as cleaning the battery terminals and checking the charging system.

By following these preventative measures, you can help ensure that your vehicle’s electrical systems remain in good working order and avoid triggering the P0602 code.

Our take

In conclusion, the P0602 code can be a frustrating issue for any vehicle owner. By understanding the potential causes of the code, how to diagnose it, and what steps you can take to fix and prevent it, you can help keep your vehicle running smoothly and avoid costly repairs down the line.

We created this guide solely for that purpose, so we hope it will help lead the way through the code and the most effective solutions.

What are the symptoms of the P0602 error code?

Common symptoms of the P0602 error code include engine stalling, poor acceleration, and a check engine light that stays on.

How is the P0602 error code diagnosed?

Diagnosing the cause of the P0602 error code typically involves using a scan tool to check for any stored trouble codes and performing a visual inspection of the ECM and its wiring. In some cases, it may be necessary to test the ECM using specialized equipment.

Can I still drive my car with the P0602 error code?

It’s generally not recommended to continue driving your car when the P0602 error code is triggered. This is because it can affect your car’s performance and cause further damage to critical components.

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  • Filip Gromovic
    Filip Gromovic

    Filip is a lifelong car enthusiast with over 3 years of experience writing about cars and had worked as a mechanic apprentice for over 5 years, gaining hands-on expertise in automotive mechanics. At REREV, he combines his passion for cars with his comprehensive knowledge to provide readers with a unique blend of technical insight and engaging storytelling that sets the bar high for automotive content.

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