AutoCodes – Infiniti – P0603 Infiniti

P0603 Infiniti Code - Engine Control Module Power Supply Circuit

Quick Answer

Battery voltage is supplied to the Engine Control Module (ECM) even when the ignition switch is turned OFF for the ECM 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, Faulty Engine Control Module (ECM). 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 Infiniti indicates Engine Control Module Power Supply Circuit.
Common causes: Common causes include Loose or poor battery terminal connection, Low battery charge, Faulty Engine Control Module (ECM).
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 31,380

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

OBDII Code P0603 Infiniti - Engine Control Module Power Supply Circuit - AutoCodes.com — P0603 Infiniti Code - Engine Control Module Power Supply Circuit

What does this mean?

What are the Possible Causes of the DTC P0603 Infiniti?

Loose or poor battery terminal connection
Low battery charge
Faulty Engine Control Module (ECM)
ECM power supply circuit is open or shorted
ECM Outdated Program

How to Fix the DTC P0603 Infiniti?

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 vehicles battery and clean terminal, once the battery is charged and the terminals are clean and secure, erase code. If the code comes back ON you may have to reprogram or replaced ECM

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0603 Infiniti 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 Infiniti code?

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

Need Help with the Code?

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

Information for Specific Infiniti Models

P0603 2006 Infiniti G35 — Engine Control Module Power Supply Circuit

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 Infiniti Code

1. What are the common symptoms of OBDII code P0603 in an Infiniti?

Common symptoms include engine stalling, rough idling, poor acceleration, and illuminated check engine light.

2. What does OBDII code P0603 indicate in an Infiniti?

OBDII code P0603 indicates a malfunction in the Engine Control Module (ECM) power supply circuit.

3. What are the possible causes of OBDII code P0603 in an Infiniti?

Possible causes include a faulty ECM power supply relay, damaged wiring or connectors in the power supply circuit, or a defective ECM.

4. How can I diagnose OBDII code P0603 in my Infiniti?

Diagnosis involves checking the power supply circuit for continuity, inspecting the ECM power supply relay, and performing a thorough visual inspection of related components.

5. Can OBDII code P0603 be fixed by resetting the ECM in an Infiniti?

Resetting the ECM may temporarily clear the code, but it will not resolve the underlying issue causing the malfunction. Proper diagnosis and repair are necessary.

6. Is it safe to continue driving with OBDII code P0603 present in my Infiniti?

Continuing to drive with OBDII code P0603 present can potentially lead to further damage to the ECM and other engine components. It is recommended to address the issue promptly.

7. How much does it typically cost to repair OBDII code P0603 in an Infiniti?

Repair costs for OBDII code P0603 can vary depending on the exact cause of the issue. It is advisable to consult a professional mechanic for an accurate diagnosis and cost estimate.

8. Can a DIY enthusiast repair OBDII code P0603 in an Infiniti?

While some DIY enthusiasts may be able to diagnose and repair simple issues related to OBDII code P0603, it is recommended to seek the expertise of a qualified mechanic for more complex problems.

9. Will OBDII code P0603 cause permanent damage to my Infiniti's engine?

If left unresolved, OBDII code P0603 can potentially cause damage to the ECM and affect engine performance. Timely diagnosis and repair are crucial to prevent further issues.

10. How often does OBDII code P0603 occur in Infiniti vehicles?

OBDII code P0603 is relatively uncommon in Infiniti vehicles but can still occur due to various factors such as aging components or electrical faults. Regular maintenance can help prevent such issues.