AutoCodes – Subaru – P0604 Subaru

P0604 Subaru Code - Internal Control Module Random Access Memory Error

Quick Answer

The PCM 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 Subaru 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 8,048

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 Subaru Description

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

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

What does this mean?

What are the Possible Causes of the DTC P0604 Subaru?

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 Subaru?

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 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 PCM.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0604 Subaru 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 Subaru code?

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

Need Help with the Code?

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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 Subaru Code

1. What are the common symptoms of OBDII code P0604 in a Subaru?

The common symptoms of OBDII code P0604 in a Subaru include engine stalling, rough idling, poor acceleration, and difficulties starting the vehicle.

2. What causes the Internal Control Module Random Access Memory Error (P0604) in a Subaru?

The P0604 code in a Subaru is typically caused by a faulty internal control module, a software issue, a corrupted memory, or a wiring problem.

3. How serious is the P0604 code in a Subaru?

The P0604 code is considered a serious issue as it can lead to poor engine performance, potential stalling, and overall drivability problems. It is recommended to address this issue promptly.

4. Can I still drive my Subaru with the P0604 code present?

It is not advisable to continue driving your Subaru with the P0604 code present, as it can result in further damage to the vehicle and compromise safety. It is recommended to have the issue diagnosed and repaired as soon as possible.

5. How is the P0604 code diagnosed in a Subaru?

Diagnosing the P0604 code in a Subaru typically involves using an OBDII scanner to retrieve the code, inspecting the internal control module and related wiring, and performing a thorough system check to identify the root cause of the issue.

6. What are some repair tips for fixing the P0604 code in a Subaru?

Repairing the P0604 code in a Subaru may involve reprogramming the internal control module, replacing the faulty module, addressing any software issues, or repairing damaged wiring. It is recommended to consult a professional mechanic for an accurate diagnosis and repair.

7. Can a DIY enthusiast fix the P0604 code in a Subaru?

While some DIY enthusiasts may have the skills to address the P0604 code in a Subaru, it is recommended to seek professional help due to the complexity of the internal control module and potential software issues involved in the repair process.

8. Will resetting the OBDII code P0604 in a Subaru make it go away permanently?

Resetting the OBDII code P0604 in a Subaru may temporarily clear the error code, but if the underlying issue is not addressed, the code is likely to reappear. It is important to diagnose and repair the root cause of the problem to prevent recurrence.

9. How much does it cost to repair the P0604 code in a Subaru?

The cost of repairing the P0604 code in a Subaru can vary depending on the extent of the damage, the parts needed for replacement, and the labor costs. It is advisable to obtain quotes from different mechanics or repair shops for an accurate estimate.

10. Can the P0604 code in a Subaru cause other problems if left unaddressed?

If left unaddressed, the P0604 code in a Subaru can potentially lead to more serious issues such as engine damage, increased fuel consumption, and safety hazards due to unexpected stalling. It is crucial to resolve the problem promptly to avoid further complications.