AutoCodesNissan – P0603 2006 Nissan Maxima

P0603 2006 Nissan Maxima 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 2006 Nissan Maxima 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 5,942
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jun 14, 2020
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Code P0603 2006 Nissan Maxima Description

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.
OBDII Code P0603 2006 Nissan Maxima - Engine Control Module Power Supply Circuit - AutoCodes.com
P0603 2006 Nissan Maxima Code - Engine Control Module Power Supply Circuit

What are the Possible Causes of the DTC P0603 2006 Nissan Maxima?

  • 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  • ECM Outdated Program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 2006 Nissan Maxima?

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.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0603 2006 Nissan Maxima 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 2006 Nissan Maxima 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 P0603 2006 Nissan Maxima Code

1. What does the OBDII code P0603 mean for a 2006 Nissan Maxima?

P0603 indicates an issue with the Engine Control Module (ECM) power supply circuit, often due to a loss of power or memory malfunction in the ECM.

2. What are common symptoms of the P0603 code on a 2006 Nissan Maxima?

Symptoms may include a check engine light, erratic engine performance, stalling, poor fuel economy, and difficulty starting the vehicle.

3. What causes the P0603 code to appear in a 2006 Nissan Maxima?

Common causes include a weak or failing battery, loose or corroded battery terminals, a faulty ECM, wiring issues, or improper ECM programming.

4. Can a weak car battery trigger the P0603 code in a 2006 Nissan Maxima?

Yes, a weak or dying battery can cause voltage fluctuations, leading to memory loss in the ECM and triggering the P0603 code.

5. How do I diagnose the P0603 code on my 2006 Nissan Maxima?

Begin by checking the battery voltage, inspecting battery connections, and scanning for other related codes. If no issues are found, test the ECM power and ground circuits.

6. Can I drive my 2006 Nissan Maxima with the P0603 code?

Driving with the P0603 code is possible but not recommended, as it may lead to poor engine performance or cause the car to stall unexpectedly.

7. What repairs can fix the P0603 code on a 2006 Nissan Maxima?

Repairs may include replacing the battery, cleaning battery terminals, repairing or replacing damaged wiring, or reprogramming or replacing the ECM.

8. Does the P0603 code always mean the ECM needs to be replaced?

No, the ECM doesn’t always need to be replaced. The issue could be related to power supply problems, poor wiring, or other external factors.

9. How much does it cost to repair the P0603 code on a 2006 Nissan Maxima?

Costs vary but can range from $100 for battery or wiring repairs to over $1,000 if the ECM requires replacement and reprogramming.

10. Can resetting the ECM clear the P0603 code on my 2006 Nissan Maxima?

Resetting the ECM may temporarily clear the code, but if the underlying issue isn’t fixed, the code is likely to return.

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