How to Fix P0605 – Internal Control Module Random Access Memory (RAM) Error

If you’re a car owner, you might have encountered various error codes that appear on your vehicle’s diagnostic system.

One such code is the P0605 error, which indicates an issue with the Internal Control Module Random Access Memory (RAM).

This error can cause a variety of problems, including poor engine performance and difficulty starting the vehicle. In this article, we will explore the causes, symptoms, diagnostic process, and effective solutions to fix the P0605 error.

So, let’s dive in and learn how to address this issue efficiently.

car vertical

Understanding the P0605 Error Code

The P0605 error code specifically relates to the Internal Control Module Random Access Memory (RAM).

The control module is an essential component of your vehicle’s electronic system, responsible for managing various functions like engine performance, transmission, and emissions control. The RAM is a crucial part of the control module, as it stores important data and instructions required for proper operation.

When the control module’s RAM encounters an error or malfunctions, the vehicle’s diagnostic system triggers the P0605 error code. This code indicates that there is a problem with the control module’s memory, potentially affecting the vehicle’s overall performance.

Causes of P0605 Error

Several factors can contribute to the occurrence of the P0605 error code. Understanding these causes can help you pinpoint the issue more accurately and take the necessary steps to fix it. The primary causes of the P0605 error are:

1. Faulty Control Module: A faulty control module itself can trigger the P0605 error code. Over time, the control module may develop internal faults, leading to RAM-related issues.

2. Software Issues: Outdated or corrupted software within the control module can also cause the P0605 error. This can occur due to various factors, such as incompatible updates or glitches in the software.

3. Electrical Problems: Faulty wiring, loose connections, or other electrical issues can disrupt the communication between the control module and the RAM, resulting in the P0605 error.

Symptoms of P0605 Error

Identifying the symptoms associated with the P0605 error can help you diagnose the problem and take appropriate actions. The common symptoms of the P0605 error include:

1. Check Engine Light: The most noticeable indication of the P0605 error is the illumination of the check engine light on your vehicle’s dashboard. This light serves as a warning sign that something is wrong with the control module.

2. Poor Engine Performance: The P0605 error can impact your vehicle’s overall performance. You may experience rough idling, stalling, or a decrease in power while driving.

3. Difficulty Starting the Vehicle: The P0605 error can also make it challenging to start your vehicle. You might encounter prolonged cranking or even complete failure to start.

Diagnostic Process

To accurately diagnose the P0605 error and ensure a proper fix, it’s essential to follow a systematic diagnostic process. Here are the steps involved:

1. Using an OBD-II Scanner: Begin by connecting an OBD-II scanner to your vehicle’s diagnostic port. This scanner will retrieve the error codes stored in the control module’s memory, including the P0605 code. Additionally, it can provide valuable information about other potential issues.

2. Inspecting Wiring and Connectors: Carefully inspect the wiring and connectors related to the control module. Look for any signs of damage, corrosion, or loose connections. Repair or replace any faulty components as necessary.

3. Testing the Control Module: To confirm if the control module is indeed causing the P0605 error, further testing is required. Consult the vehicle’s service manual or seek professional assistance to perform diagnostic tests specific to your vehicle’s make and model.

Fixing P0605 Error

Once you have identified that the P0605 error is due to a control module RAM issue, you can proceed with the appropriate solutions. Here are some effective methods to fix the P0605 error:

1. Resetting the Control Module: Sometimes, the P0605 error can be a temporary glitch. You can attempt to reset the control module by disconnecting the battery for about 15 minutes. This action may clear the error code and restore normal functionality.

2. Updating the Control Module Software: Check if there are any available software updates for your vehicle’s control module. Visit the manufacturer’s website or consult a professional to obtain and install the latest software version. This can rectify software-related issues causing the P0605 error.

3. Repairing or Replacing the Control Module: If all else fails, and the control module is determined to be faulty, you may need to repair or replace it. This typically requires professional assistance, as it involves programming and reconfiguring the new or repaired control module to match your vehicle’s specifications.

Preventive Measures

To minimize the occurrence of the P0605 error and other related issues, consider implementing the following preventive measures:

  • Regularly update your vehicle’s software and firmware as recommended by the manufacturer.
  • Follow proper maintenance schedules, including periodic inspections and servicing of the control module.
  • Take immediate action if you notice any unusual symptoms or warning lights on your vehicle’s dashboard.
  • Ensure the vehicle’s electrical system is in good condition, addressing any electrical problems promptly.


Dealing with the P0605 error code can be frustrating, but with the right knowledge and steps, you can effectively address the issue. By understanding the causes, symptoms, and diagnostic process, you can accurately identify the problem and choose the appropriate solution. Whether it’s resetting the control module, updating software, or seeking professional help, taking prompt action will ensure your vehicle’s optimal performance and reliability.


1. Can I fix the P0605 error myself, or should I seek professional help?

While simple solutions like resetting the control module can be attempted by car owners, diagnosing and repairing the underlying cause of the P0605 error may require professional assistance. It is advisable to consult a certified mechanic or technician for complex issues or if you are unsure of your capabilities.

2. How much does it cost to repair or replace a faulty control module?

The cost of repairing or replacing a control module can vary depending on several factors, such as the make and model of your vehicle, the extent of the damage, and labor charges. It’s best to consult with a professional or authorized service center to get an accurate estimate for your specific case.

3. Are there any temporary fixes for the P0605 error?

While resetting the control module may temporarily clear the error code, it’s essential to diagnose and address the underlying cause. Ignoring the issue or relying solely on temporary fixes can lead to further problems and potential damage to your vehicle’s systems.