AutoCodes – Generic – P0603

P0603 Code - Internal Control Module Keep Alive Memory Error

Quick Answer

Battery voltage is supplied to the Engine Control Module (ECM) / Powertrain Control Module (PCM) even when the ignition switch is turned OFF for the ECM/PCM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc. Common causes include Loose or poor battery terminal connection, Low battery charge, Engine Control Module (ECM) / Powertrain Control Module (PCM) 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: P0603 indicates Internal Control Module Keep Alive Memory Error.
Common causes: Common causes include Loose or poor battery terminal connection, Low battery charge, Engine Control Module (ECM) / Powertrain Control Module (PCM) 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 94,670

How popular is this code, among other codes? Medium

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 Mar 17, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0603 Description

OBDII Code P0603 - Internal Control Module Keep Alive Memory Error - AutoCodes.com — P0603 Code - Internal Control Module Keep Alive Memory Error

What does this mean?

What are the Possible Causes of the DTC P0603?

Loose or poor battery terminal connection
Low battery charge
Engine Control Module (ECM) / Powertrain Control Module (PCM) power supply circuit is open or shorted
ECM/PCM Programing
Faulty ECM/PCM

How to Fix the DTC P0603?

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

Start by charging the vehicle's battery and clean the terminal, once the battery is charged and the terminals are clean and secured, erase the code. If the code comes back ON, then you may have to reprogram or replace Engine Control Module (ECM) / Powertrain Control Module (PCM)

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0603 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 P0603 code?

Need more information on how to fix the P0603 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0603 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0603 Acura — ECM Internal Keep Alive Memory Error
P0603 BMW — ECM Self Check Fault
P0603 Buick — Control Module Long Term Memory Reset
P0603 Cadillac — Control Module Long Term Memory Reset
P0603 Chevrolet — Control Module Long Term Memory Reset
P0603 Ford — ECM Keep Alive Memory Test Error
P0603 GMC — Control Module Long Term Memory Reset
P0603 Honda — ECM Internal Keep Alive Memory Error
P0603 Infiniti — Engine Control Module Power Supply Circuit
P0603 Isuzu — Internal Processor Error
P0603 Mazda — ECM malfunction
P0603 Mercedes-Benz — Internal Control Module Keep Alive Memory Error
P0603 MINI — ECM Self Check Fault
P0603 Mitsubishi — EEPROM Malfunction
P0603 Nissan — Engine Control Module Power Supply Circuit
P0603 Saab — Control Module Long Term Memory Reset
P0603 Volkswagen — Internal Control Module Keep Alive Memory Error
P0603 Volvo — Internal Control Module Keep Alive Memory Error

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 P0603 Code

1. What are the common symptoms of OBDII code P0603 (Internal Control Module Keep Alive Memory Error)?

- Common symptoms include engine stalling, rough idling, issues with starting the vehicle, and the illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P0603?

- The code P0603 can be caused by a faulty powertrain control module (PCM), a dead or weak battery, a software issue within the PCM, or wiring problems.

3. How can I diagnose OBDII code P0603?

- To diagnose the code P0603, a technician will use a diagnostic scanner to retrieve the specific error code and then perform further testing to identify the root cause, such as checking the battery voltage and inspecting the PCM connections.

4. Can I continue driving my vehicle with OBDII code P0603?

- It is not recommended to continue driving your vehicle with the code P0603, as it can lead to potential safety hazards and further damage to the vehicle's components. It's best to address the issue promptly.

5. How can I repair OBDII code P0603?

- Repairing OBDII code P0603 typically involves replacing the PCM if it is found to be faulty, ensuring the battery is in good condition, updating the PCM software if necessary, and checking and repairing any damaged wiring or connections.

6. Is it possible to reset OBDII code P0603 without fixing the underlying issue?

- While clearing the error code may temporarily turn off the Check Engine Light, the code is likely to reappear if the underlying issue is not addressed. It is important to fix the root cause of the problem to prevent further issues.

7. Can a DIY enthusiast repair OBDII code P0603 at home?

- Repairing OBDII code P0603 may require advanced diagnostic tools and technical knowledge, so it is recommended to seek assistance from a professional mechanic to properly diagnose and repair the issue.

8. How much does it cost to fix OBDII code P0603?

- The cost of repairing OBDII code P0603 can vary depending on the underlying cause of the issue, the cost of parts needed for repair, and the labor rates of the repair shop. It's best to get a quote from a mechanic.

9. Is OBDII code P0603 a common issue in certain vehicle makes and models?

- OBDII code P0603 can occur in various vehicle makes and models that utilize an OBDII system. However, it may be more prevalent in certain vehicles known for PCM or electrical system issues.

10. Can a bad PCM cause other OBDII codes to appear along with P0603?

- Yes, a faulty PCM can cause other OBDII codes to appear in addition to P0603, as the PCM plays a crucial role in the vehicle's operation and can impact various systems. It's important to address any related codes during diagnosis and repair.