Engine-CodesGMC – P0604 2018 GMC Sierra

P0604 2018 GMC Sierra Code - Control Module Random Access Memory Performance

Quick Answer

The P0604 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates an issue with the Control Module Random Access Memory (RAM) performance. Common causes include Electrical interference from aftermarket accessories, Faulty ECM, Software malfunction. 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 2018 GMC Sierra indicates Control Module Random Access Memory Performance.
Common causes
Common causes include Electrical interference from aftermarket accessories, Faulty ECM, Software malfunction.
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 17, 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 2018 GMC Sierra Description

The P0604 diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates an issue with the Control Module Random Access Memory (RAM) performance. The Engine Control Module (ECM) or Powertrain Control Module (PCM) in the vehicle uses RAM to store temporary data and instructions for various functions. When the ECM detects that the RAM is not performing as expected, it triggers the P0604 code.

OBDII Code P0604 2018 GMC Sierra - Control Module Random Access Memory Performance
P0604 2018 GMC Sierra Code - Control Module Random Access Memory Performance

Common Causes of P0604 2018 GMC Sierra

  1. Electrical interference from aftermarket accessories
  2. Faulty ECM
  3. Software malfunction
  4. Wiring issues
  5. Corrosion or poor connections in the ECM circuitry

Symptoms of P0604 2018 GMC Sierra

  1. Check Engine Light illuminated
  2. Engine running rough or misfiring
  3. Reduced fuel efficiency
  4. Difficulty starting the vehicle
  5. Loss of power or acceleration

How to Fix P0604 2018 GMC Sierra

  1. Diagnose the issue using a scan tool to retrieve the DTC and perform a thorough inspection of the ECM and related components.
  2. Check for any loose or damaged wiring connections and repair as necessary.
  3. Test the ECM for proper functionality and consider reprogramming or replacing it if deemed faulty.
  4. Clear the DTC and perform a test drive to ensure the issue has been resolved.
  5. Reset the ECM and perform a relearn procedure to recalibrate the system.

Cost to Fix P0604 2018 GMC Sierra

The cost of repairing a P0604 code on a 2018 GMC Sierra can vary depending on the specific cause of the issue and the labor rates in your area. On average, you can expect to pay between $200 and $500 for parts and labor. Keep in mind that diagnostic time and labor rates at auto repair shops can fluctuate, so it's advisable to obtain quotes from multiple sources before proceeding with the repair.

Tech Notes for P0604 2018 GMC Sierra

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

Need more information about the P0604 2018 GMC Sierra code?

Need more information on how to fix the P0604 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0604 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 2018 GMC Sierra Code

No Frequently Asked Questions about P0604 2018 GMC Sierra Code found.

Discuss the causes and fixes for P0604 2018 GMC Sierra OBDII Code

Code P0604 2018 GMC Sierra comments

No comments found for this page.