AutoCodes – Nissan – P0456 2004 Nissan Altima Sedan

P0456 2004 Nissan Altima Sedan Code - Evaporative Emission Control System Very Small Leak Detected

Quick Answer

This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P0456 2004 Nissan Altima Sedan indicates Evaporative Emission Control System Very Small Leak Detected.
Common causes: Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 3,120

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 25, 2024

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0456 2004 Nissan Altima Sedan Description

This diagnosis detects leaks in the Evaporative Emission System (EVAP) purge line using engine intake manifold vacuum. If pressure does not increase, the Engine Control Module (ECM) will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition.
The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.

OBDII Code P0456 2004 Nissan Altima Sedan - Evaporative Emission Control System Very Small Leak Detected - AutoCodes.com — P0456 2004 Nissan Altima Sedan Code - Evaporative Emission Control System Very Small Leak Detected

What does this mean?

What are the Possible Causes of the DTC P0456 2004 Nissan Altima Sedan?

Missing or loose fuel cap
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap
Evaporative Emission (EVAP) canister or fuel tank leaks
Evaporative Emission (EVAP) system hose leaking
Fuel tank leaking

How to Fix the DTC P0456 2004 Nissan Altima Sedan?

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

The fuel tank filler cap and the Purge Volume Control Valve are the more common problems that will trigger the P0456 code on Nissan vehicles.

There is a factory Nissan service bulletin to help diagnose the P0456 code:
Nissan Factory Service Bulletin OBDII Code P0456

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0456 2004 Nissan Altima Sedan 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 P0456 2004 Nissan Altima Sedan 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 P0456 2004 Nissan Altima Sedan Code

1. What are the common symptoms of OBDII code P0456 on a 2004 Nissan Altima Sedan?

- Common symptoms include the illumination of the check engine light, a noticeable fuel odor, and potential difficulties during the vehicle's emissions testing.

2. What are the possible causes of OBDII code P0456 on a 2004 Nissan Altima Sedan?

- The code P0456 typically indicates a very small leak in the evaporative emission control system. Potential causes include a loose or damaged gas cap, a cracked or loose EVAP system hose, or a faulty EVAP canister purge valve.

3. How can I diagnose the source of the very small leak triggering OBDII code P0456 on my 2004 Nissan Altima Sedan?

- To pinpoint the source of the leak, you can perform a visual inspection of the EVAP system components, check the gas cap for tightness and damage, use a smoke machine to detect leaks, and conduct a system pressure test.

4. Can a loose gas cap trigger OBDII code P0456 on a 2004 Nissan Altima Sedan?

- Yes, a loose or improperly sealed gas cap is a common cause of the very small leak detected by the evaporative emission control system, leading to the illumination of the check engine light with code P0456.

5. Is it safe to continue driving my 2004 Nissan Altima Sedan with OBDII code P0456 present?

- While code P0456 usually doesn't pose an immediate threat to vehicle safety, it is recommended to address the issue promptly to prevent potential fuel economy issues and ensure proper emissions control.

6. What are some DIY repair tips for resolving OBDII code P0456 on a 2004 Nissan Altima Sedan?

- DIY repair options include inspecting and tightening the gas cap, visually checking for damaged hoses, using an OBDII scanner to reset the code after addressing the issue, and ensuring all EVAP system components are properly connected.

7. Can a faulty EVAP canister purge valve trigger OBDII code P0456 on a 2004 Nissan Altima Sedan?

- Yes, a malfunctioning EVAP canister purge valve can lead to improper pressure in the evaporative emission control system, potentially causing a very small leak to trigger code P0456.

8. How much can I expect to pay for professional repairs related to OBDII code P0456 on a 2004 Nissan Altima Sedan?

- The cost of professional repairs for code P0456 can vary depending on the exact cause of the issue and labor rates in your area. Expect costs to range from $100 to $500, with parts and labor included.

9. Will clearing the OBDII code P0456 on a 2004 Nissan Altima Sedan make the problem go away permanently?

- Clearing the code without addressing the underlying issue will not permanently resolve the problem. It is crucial to diagnose and repair the root cause of the very small leak in the evaporative emission control system to prevent code P0456 from reoccurring.

10. How long does it typically take to diagnose and repair OBDII code P0456 on a 2004 Nissan Altima Sedan?

- The diagnostic process and repair for code P0456 can usually be completed within a few hours, depending on the complexity of the issue and the availability of parts needed for the repair.