AutoCodes – Mercedes-Benz – P0604 Mercedes-Benz

P0604 Mercedes-Benz Code - Internal Control Module Random Access Memory Error

Quick Answer

The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. Common causes include Loose or poor battery terminal connection, Low battery charge, ECM power supply circuit is open or shorted. 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 Mercedes-Benz indicates Internal Control Module Random Access Memory Error.
Common causes: Common causes include Loose or poor battery terminal connection, Low battery charge, ECM power supply circuit is open or shorted.
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.

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Code Popularity 16,431

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0604 Mercedes-Benz Description

The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check insures that the ECM is functioning properly. If any malfunction is detected, the will ECM will set the code and illuminate the engine light.

OBDII Code P0604 Mercedes-Benz - Internal Control Module Random Access Memory Error - AutoCodes.com — P0604 Mercedes-Benz Code - Internal Control Module Random Access Memory Error

What does this mean?

What are the Possible Causes of the DTC P0604 Mercedes-Benz?

Loose or poor battery terminal connection
Low battery charge
ECM power supply circuit is open or shorted
ECM Programing
Faulty ECM

How to Fix the DTC P0604 Mercedes-Benz?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

Check the ECM/PCM fuse, if fuse is OK try erasing the code first and if the code comes back you may have to reprogram or replaced the ECM/PCM.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0604 Mercedes-Benz code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0604 Mercedes-Benz code?

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

Need Help with the Code?

Get the P0604 Mercedes-Benz 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 Mercedes-Benz Code

1. What does the OBDII code P0604 mean on a Mercedes-Benz?

P0604 indicates an "Internal Control Module Random Access Memory (RAM) Error," meaning the Engine Control Module (ECM) has detected an issue with its internal memory.

2. What are the common symptoms of a P0604 code in a Mercedes-Benz?

Symptoms may include difficulty starting the engine, poor performance, stalling, erratic shifting (in automatic transmissions), or the Check Engine Light being illuminated.

3. What causes the P0604 code in a Mercedes-Benz?

Common causes include a corrupted ECM, voltage spikes, water damage to the ECM, software glitches, or a failing ECM.

4. Can a weak battery cause the P0604 code in a Mercedes-Benz?

Yes, a weak or failing battery, or poor electrical connections, can cause voltage irregularities that may trigger this code.

5. How do you diagnose a P0604 code on a Mercedes-Benz?

Diagnosis typically involves checking the battery and charging system, inspecting ECM connections for corrosion or damage, and using specialized diagnostic tools to test the ECM.

6. Can the P0604 code be cleared without repairs?

Clearing the code without addressing the root cause may temporarily turn off the Check Engine Light, but the issue is likely to recur until repairs are performed.

7. Is an ECM replacement always necessary for a P0604 code?

Not always. The issue could be caused by wiring problems, battery issues, or software glitches. ECM replacement should only be done after thorough diagnosis.

8. How can I prevent the P0604 code from occurring in my Mercedes-Benz?

Regularly maintain the battery and charging system, keep electrical connections clean and secure, and avoid jump-starting the vehicle improperly.

9. Can driving with a P0604 code damage my Mercedes-Benz?

While it may not cause immediate damage, continued driving with an unresolved P0604 code could lead to performance issues, stalling, and potential safety risks.

10. How much does it cost to repair a P0604 code on a Mercedes-Benz?

Repair costs can vary widely. Battery or wiring fixes may cost $100â€“$300, while ECM replacement can range from $800â€“$2,000, depending on the model and labor rates.