Engine-CodesGeneric – P0604

P0604 Code - Internal Control Module Random Access Memory Error

Quick Answer

The P0604 diagnostic trouble code (DTC) refers to an Internal Control Module Random Access Memory (RAM) Error. Common causes include Faulty ECM/PCM hardware, Software glitches or corrupted data, Electrical issues such as a poor connection or damaged wiring. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0604 indicates Internal Control Module Random Access Memory Error.
Common causes
Common causes include Faulty ECM/PCM hardware, Software glitches or corrupted data, Electrical issues such as a poor connection or damaged wiring.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 06, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0604 Description

The P0604 diagnostic trouble code (DTC) refers to an Internal Control Module Random Access Memory (RAM) Error. This code indicates that there is a malfunction in the vehicle's Engine Control Module (ECM) or Powertrain Control Module (PCM) where the random access memory is stored. The ECM/PCM is responsible for controlling various functions within the vehicle, such as fuel injection, ignition timing, and transmission shifting. The random access memory is used to store temporary data and instructions that the ECM/PCM needs to operate effectively.

OBDII Code P0604 - Internal Control Module Random Access Memory Error
P0604 Code - Internal Control Module Random Access Memory Error

Common Causes of P0604

  1. Faulty ECM/PCM hardware
  2. Software glitches or corrupted data
  3. Electrical issues such as a poor connection or damaged wiring
  4. Weak or dead battery affecting the ECM/PCM
  5. Environmental factors such as extreme temperatures or moisture

Symptoms of P0604

  1. Check Engine Light illuminated on the dashboard
  2. Rough idling or engine misfires
  3. Decreased fuel efficiency
  4. Stalling or difficulty starting the vehicle
  5. Intermittent electrical issues

How to Fix P0604

  1. Begin by diagnosing the specific cause of the P0604 code using a diagnostic scan tool to retrieve additional trouble codes and data stream information.
  2. Inspect the ECM/PCM for any visible signs of damage or corrosion. Check the connections and wiring harness for any loose or damaged connections.
  3. Perform a software update or reflash the ECM/PCM to fix any software glitches or corrupted data.
  4. Replace the ECM/PCM if it is determined to be faulty. This may require programming and reprogramming to ensure compatibility with the vehicle's systems.
  5. Test drive the vehicle to ensure that the P0604 code does not return and that the symptoms associated with it have been resolved.

Cost to Fix P0604

The typical repair costs for addressing a P0604 code can range from $200 to $800, depending on the specific cause of the issue and the required repairs. This estimate includes the cost of parts such as a new ECM/PCM, software updates, and labor costs for diagnosis and repair. It is important to note that the actual cost may vary based on factors such as location, vehicle make and model, and labor rates at the auto repair shop. It is advisable to consult with a certified mechanic or dealership for a more accurate estimate based on your vehicle's specific needs.

Tech Notes for P0604

Check the Engine Control Module (ECM) / Powertrain Control Module (PCM) fuse, if the fuse is OK try erasing the code first and if the code comes back you may have to reprogram or replace the ECM/PCM.

When is the Code Detected?

Indicates the ECM has experienced an internal memory fault.

Need more information about the P0604 code?

Need more information on how to fix the P0604 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0604 code diagnosed by a professional: Find a repair shop in your area

Code P0604 Information for Specific Makes

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0604 Code

No Frequently Asked Questions about P0604 Code found.

Discuss the causes and fixes for P0604 OBDII Code

Code P0604 comments

No comments found for this page.