How to Fix P0604 – Internal Control Module Keep Alive Memory (KAM) Error

When it comes to car troubles, a P0604 error can be a cause for concern. This error code refers to an issue with the Internal Control Module’s Keep Alive Memory (KAM).

The KAM is an essential component of the control module, responsible for retaining critical data even when the vehicle is turned off.

Fixing the P0604 error promptly is crucial to ensure the smooth functioning of your vehicle and prevent further complications.

Understanding the Internal Control Module (ICM)

The Internal Control Module, also known as the Engine Control Unit (ECU) or Powertrain Control Module (PCM), is a vital part of modern vehicles. It acts as the brain of the car, monitoring various systems and controlling their functions.

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The Keep Alive Memory (KAM) within the ICM stores crucial data, such as learned parameters and adaptive values. This data is essential for the proper functioning of the vehicle.

Symptoms of P0604 Error

Identifying the symptoms associated with the P0604 error can help you diagnose the issue promptly. Some common signs of this error include:

  • Check Engine Light (CEL) illuminated on the dashboard
  • Reduced engine performance or power
  • Difficulty starting the vehicle
  • Transmission shifting issues
  • Loss of certain vehicle features or functions

Causes of P0604 Error

Several factors can contribute to the occurrence of the P0604 error. Some potential causes include:

  • Power surges or voltage fluctuations
  • Battery or alternator problems
  • Faulty wiring or connectors
  • Software glitches or corrupted data within the ICM

Diagnostic Process

Diagnosing the P0604 error requires a systematic approach. Here is a step-by-step guide to help you identify the issue:

  1. Use an OBD-II scanner to retrieve the error code and any additional codes present.
  2. Inspect the battery and alternator for any signs of damage or malfunctions.
  3. Check the wiring and connectors related to the ICM for loose connections or damage.
  4. Use diagnostic resources or consult a professional for further guidance if needed.

Fixing the P0604 Error

Once you have identified the cause of the P0604 error, you can proceed with the necessary repairs. Follow these steps to fix the error:

  1. Disconnect the battery to ensure safety during the repair process.
  2. Locate the ICM in your vehicle. It is typically found near the engine compartment.
  3. Remove any components obstructing access to the ICM, such as air intake tubes or engine covers.
  4. Carefully disconnect the wiring harnesses and connectors attached to the ICM.
  5. Remove the faulty ICM from its mounting location.
  6. Install the new ICM in the correct orientation and securely fasten it.
  7. Reconnect the wiring harnesses and connectors to the new ICM.
  8. Reinstall any components that were removed during the process.
  9. Reconnect the battery and ensure all connections are secure.
  10. Start the vehicle and check if the P0604 error code has been resolved.

Tips for a Successful Repair

To increase the likelihood of a successful repair, consider the following tips:

  • Ensure you have the correct replacement ICM for your specific vehicle make and model.
  • Take pictures or label the wiring connections before disconnecting them to facilitate reassembly.
  • Double-check all connections and fasteners for proper installation.
  • Consult the vehicle’s service manual or online resources for additional guidance if needed.
  • If you are unsure about any step of the repair process, seek assistance from a qualified professional.

Preventing Future Occurrences

To prevent the P0604 error from happening again, follow these preventive measures:

  • Maintain a healthy electrical system by regularly inspecting and replacing worn-out batteries or faulty alternators.
  • Avoid power surges or voltage fluctuations by using surge protectors or stabilizers when jump-starting or connecting electronic devices to your vehicle.
  • Be cautious when handling the wiring and connectors related to the ICM, ensuring they are not damaged during repairs or modifications.
  • Perform regular maintenance checks and address any potential issues promptly to prevent further complications.


Fixing the P0604 error related to the Internal Control Module’s Keep Alive Memory (KAM) is essential for maintaining the optimal performance of your vehicle. By understanding the symptoms, causes, and diagnostic process, you can effectively address this error. Follow the step-by-step repair instructions and utilize the provided tips for a successful resolution. Remember to prioritize safety and seek professional assistance if needed. By taking proactive measures, you can prevent future occurrences of the P0604 error and enjoy a reliable driving experience.

FAQs (Frequently Asked Questions)

Can I drive my vehicle with a P0604 error?

  1. It is generally not recommended to drive your vehicle with a P0604 error as it may affect the vehicle’s performance and potentially lead to further complications. It is advisable to address the issue promptly.

Can I fix the P0604 error myself, or should I consult a professional?

  1. While some DIY enthusiasts may be able to fix the P0604 error themselves, it is essential to have a good understanding of automotive systems and access to the necessary tools. If you are unsure or uncomfortable with the repair process, it is recommended to consult a professional mechanic.

Is the P0604 error specific to a particular vehicle make or model?

  1. The P0604 error can occur in various vehicle makes and models. However, it is always best to consult the specific diagnostic information for your vehicle to ensure accurate diagnosis and repair.