AutoCodes – Mazda – P0604 Mazda

P0604 Mazda Code - ECM RAM 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 Mazda indicates ECM RAM 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 3,842

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 Mazda 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 ECM will set the code and illuminate the engine light.

OBDII Code P0604 Mazda - ECM RAM error - AutoCodes.com — P0604 Mazda Code - ECM RAM error

What does this mean?

What are the Possible Causes of the DTC P0604 Mazda?

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 Mazda?

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 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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0604 Mazda 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.

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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 Mazda Code

1. What does the OBDII code P0604 mean on a Mazda?

P0604 indicates an ECM RAM error, meaning there is an issue with the Random Access Memory (RAM) in the Engine Control Module (ECM).

2. What are common symptoms of a P0604 code in a Mazda?

Symptoms may include engine stalling, poor performance, difficulty starting, reduced fuel efficiency, and the check engine light being illuminated.

3. What causes the P0604 ECM RAM error code in a Mazda?

Common causes include a faulty ECM, poor electrical connections, damaged wiring, or voltage issues such as a weak or failing battery.

4. Can I continue driving my Mazda with a P0604 code?

While the vehicle may still be drivable, it's not recommended as the issue could lead to further engine performance problems or component damage.

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

A technician will use a scan tool to verify the code, inspect the ECM wiring and connections, test the battery and charging system, and potentially perform ECM diagnostics.

6. Can a weak battery trigger a P0604 code on a Mazda?

Yes, a weak or failing battery can cause low voltage to the ECM, potentially triggering the P0604 code.

7. How do you fix a P0604 error code in a Mazda?

Repairs may include cleaning and securing ECM connections, repairing damaged wiring, replacing the battery, or, in severe cases, replacing the ECM.

8. Is ECM replacement always necessary for a P0604 code in a Mazda?

No, ECM replacement is only necessary if diagnostics confirm the ECM is faulty. It could also be a wiring or electrical issue.

9. How much does it cost to fix a P0604 code in a Mazda?

Costs vary depending on the root cause. Simple fixes like repairing wiring or replacing a battery may cost under $200, while ECM replacement can exceed $1,000.

10. Can I reset the P0604 code on my Mazda without repairing the issue?

While clearing the code with a scan tool might temporarily turn off the check engine light, the underlying issue must be resolved to prevent the code from returning.